Abrasive article and method of forming

ABSTRACT

An abrasive article including a substrate having an elongated body, a tacking layer overlying the substrate, and a first type of abrasive particle overlying the tacking layer and defining a first abrasive particle concentration at least about 10 particles per mm of substrate.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority under 35 U.S.C. §120 to and is acontinuation of U.S. application Ser. No. 13/930,259 entitled “AbrasiveArticle and Method of Forming,” by Yinggang Tian et al., filed Jun. 28,2013, which in turn claims priority under 35 U.S.C. §119(e) to U.S.Patent Application No. 61/666,436 entitled “Abrasive Article and Methodof Forming,” by Yinggang Tian, Paul W. Rehrig, Arup K. Khaund, AvantiJain, Wei Che, Susanne Liebelt, and Vincent Tesi, filed Jun. 29, 2012,which applications are both assigned to the current assignee hereof andboth incorporated herein by reference in their entirety.

BACKGROUND

Field of the Disclosure

The following is directed to methods of forming abrasive articles, andparticularly, single-layered abrasive articles.

Description of the Related Art

A variety of abrasive tools have been developed over the past centuryfor various industries for the general function of removing materialfrom a workpiece, including for example, sawing, drilling, polishing,cleaning, carving, and grinding. In particular reference to theelectronics industry, abrasive tools suitable for slicing crystal ingotsof material to form wafers is particularly pertinent. As the industrycontinues to mature, ingots have increasingly larger diameters, and ithas become acceptable to use loose abrasives and wire saws for suchworks due to yield, productivity, affected layers, dimensionalconstraints and other factors.

Generally, wire saws are abrasive tools that include abrasive particlesattached to a long length of wire that can be spooled at high speeds toproduce a cutting action. While circular saws are limited to a cuttingdepth of less than the radius of the blade, wire saws can have greaterflexibility allowing for cutting of straight or profiled cutting paths.

Various approaches have been taken in conventional fixed abrasive wiresaws, such as producing these articles by sliding steel beads over ametal wire or cable, wherein the beads are separated by spacers. Thesebeads may be covered by abrasive particles which are commonly attachedby either electroplating or sintering. However, electroplating andsintering operations can be time consuming and thus costly ventures,prohibiting rapid production of the wire saw abrasive tool. Most ofthese wire saws have been used in applications, where kerf loss is notso dominating as in electronics applications, often to cut stone ormarble. Some attempts have been made to attach abrasive particles viachemical bonding processes, such as brazing, but such fabricationmethods reduce the tensile strength of the wire saw, and the wire sawbecomes susceptible to breaking and premature failure during cuttingapplications under high tension. Other wire saws may use a resin to bindthe abrasives to the wire. Unfortunately, the resin bonded wire sawstend to wear quickly and the abrasives are lost well before the usefullife of the particles is realized, especially when cutting through hardmaterials.

Accordingly, the industry continues to need improved abrasive tools,particularly in the realm of wire sawing.

SUMMARY

According to a first aspect, a method of forming an abrasive articleincludes providing a substrate having an elongated body, forming atacking layer overlying a surface of the substrate, the tacking layercomprising tin, and providing a first type of abrasive particle having afirst average abrasive particle concentration of at least about 10particles per mm of substrate.

According to a second aspect, an abrasive article includes a substratehaving an elongated body, a tacking layer overlying a surface of thesubstrate, and a first type of abrasive particle overlying the tackinglayer, wherein the first type of abrasive particle defines a first widegrit size distribution wherein at least 80% of the first type ofabrasive particle has an average grit size contained within a grit sizerange of at least about 30 microns over a range of average grit sizesbetween about 1 micron to about 100 microns.

For yet another aspect, an abrasive article includes a substrate havingan elongated body, a tacking layer overlying the substrate comprisingtin, and at least one of a) a first type of abrasive particle having anaverage particle size less than about 20 microns overlying thesubstrate, having a first average abrasive particle concentration forthe first type of abrasive particle of at least about 20 particles permm of substrate and not greater than about 800 particles per mm of thesubstrate, and at least about 0.5 carats per kilometer of the substrateand not greater than about 10 carats per kilometer of substrate, and b)a second type of abrasive particle having an average particle size of atleast about 20 microns overlying the substrate, having a second averageabrasive particle concentration for the second type of abrasive particleof at least about 10 particles per mm of substrate and not greater thanabout 200 particles per mm of the substrate and at least about 3 caratsper kilometer of the substrate and not greater than about 200 carats perkilometer of substrate

Still, in another aspect, an abrasive article includes a substratehaving an elongated body, a tacking layer overlying the substrate, and afirst type of abrasive particle overlying the tacking layer and defininga first abrasive particle concentration at least about 10 particles permm of substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be better understood, and its numerousfeatures and advantages made apparent to those skilled in the art byreferencing the accompanying drawings.

FIG. 1 includes a flow chart providing a process for forming an abrasivearticle in accordance with an embodiment.

FIG. 2A includes a cross-sectional illustration of a portion of anabrasive article in accordance with an embodiment.

FIG. 2B includes a cross-sectional illustration of a portion of anabrasive article including a barrier layer in accordance with anembodiment.

FIG. 2C includes a cross-sectional illustration of a portion of anabrasive article including an optional coating layer in accordance withan embodiment.

FIG. 2D includes a cross-sectional illustration of a portion of anabrasive article including a first type of abrasive particle and asecond type of abrasive particle in accordance with an embodiment.

FIG. 3 includes a magnified image of an abrasive article formedaccording to an embodiment.

FIG. 4 includes a magnified image of an abrasive article formedaccording to another embodiment.

FIG. 5 includes a magnified image of an abrasive article formedaccording to another embodiment.

FIG. 6 includes a magnified image of an abrasive article formedaccording to yet another embodiment.

FIG. 7 includes a magnified image of an abrasive article formedaccording to still another embodiment.

FIG. 8 includes a magnified image of an abrasive article formedaccording to another embodiment.

FIG. 9 includes an illustration of an exemplary agglomerated particleaccording to an embodiment.

FIG. 10A includes an illustration of a portion of an abrasive articleaccording to an embodiment.

FIG. 10B includes a cross-sectional illustration of a portion of theabrasive article of FIG. 10A according to an embodiment.

FIG. 10C includes an illustration of a portion of an abrasive articleaccording to an embodiment.

FIG. 11A includes an illustration of a portion of an abrasive articleincluding a lubricious material according to an embodiment.

FIG. 11B includes an illustration of a portion of an abrasive articleincluding a lubricious material according to an embodiment.

FIG. 12A includes an illustration of a portion of an abrasive articleincluding an abrasive particle having an exposed surface according to anembodiment.

FIG. 12B includes a picture of a portion of an abrasive articleincluding abrasive particles having exposed surfaces according to anembodiment.

FIG. 13 includes a cross-sectional picture of an abrasive articleincluding abrasive agglomerates according to an embodiment.

FIG. 14 includes a chart of relative wafer break strength for wafersprocessed by a conventional sample and wafers processed by an abrasivearticle representative of an embodiment.

FIG. 15 includes an illustration of a reel-to-reel machine using anabrasive article to slice a workpiece.

FIG. 16 includes an illustration of an oscillation machine using anabrasive article to slice a workpiece.

FIG. 17 includes an exemplary plot of wire speed versus time for asingle cycle of a variable rate cycle operation.

FIG. 18A includes a magnified image of a conventional abrasive article.

FIG. 18B includes a magnified image of a conventional abrasive article.

FIG. 18C includes a magnified image of a conventional abrasive article.

DETAILED DESCRIPTION

The following is directed to abrasive articles, and particularlyabrasive articles suitable for abrading and sawing through workpieces.In particular instances, the abrasive articles herein can form wiresaws, which may be used in processing of sensitive, crystallinematerials in the electronics industry, optics industry, and otherassociated industries.

FIG. 1 includes a flow chart providing a process of forming an abrasivearticle in accordance with an embodiment. The process can be initiatedat step 101 by providing a substrate. The substrate can provide asurface for affixing abrasive materials thereto, thus facilitating theabrasive capabilities of the abrasive article.

In accordance with an embodiment, the process of providing a substratecan include a process of providing a substrate having an elongated body.In particular instances, the elongated body can have an aspect ratio oflength:width of at least 10:1. In other embodiments, the elongated bodycan have an aspect ratio of at least about 100:1, such as at least1000:1, or even at least about 10,000:1. The length of the substrate canbe the longest dimension measured along a longitudinal axis of thesubstrate. The width can be a second longest (or in some cases smallest)dimension of the substrate measured perpendicular to the longitudinalaxis.

Furthermore, the substrate can be in the form of elongated body having alength of at least about 50 meters. In fact, other substrates can belonger, having an average length of at least about 100 meters, such asat least about 500 meters, at least about 1,000 meters, or even at leastabout 10,000 meters.

Furthermore, the substrate can have a width that may not be greater thanabout 1 cm. In fact, the elongated body can have an average width of notgreater than about 0.5 cm, such as not greater than about 1 mm, notgreater than about 0.8 mm, or even not greater than about 0.5 mm Still,the substrate may have an average width of at least about 0.01 mm, suchas at least about 0.03 mm It will be appreciated that the substrate canhave an average width within a range between any of the minimum andmaximum values noted above.

In certain embodiments, the elongated body can be a wire having aplurality of filaments braided together. That is, the substrate can beformed of many smaller wires wound around each other, braided together,or fixed to another object, such as a central core wire. Certain designsmay utilize plano wire as a suitable structure for the substrate. Forexample, the substrate can be a high strength steel wire having a breakstrength of at least about 3 GPa. The substrate break strength can bemeasured by ASTM E-8 for tension testing of metallic materials withcapstan grips. The wire may be coated with a layer of a particularmaterial, such as a metal, including for example, brass.

The elongated body can have a certain shape. For example, the elongatedbody can have a generally cylindrical shape such that it has a circularcross-sectional contour. In using elongated bodies having a circularcross-sectional shape, as viewed in a plane extending transversely tothe longitudinal axis of the elongated body.

The elongated body can be made of various materials, including forexample, inorganic materials, organic materials (e.g., polymers andnaturally occurring organic materials), and a combination thereof.Suitable inorganic materials can include ceramics, glasses, metals,metal alloys, cermets, and a combination thereof. In certain instances,the elongated body can be made of a metal or metal alloy material. Forexample, the elongated body may be made of a transition metal ortransition metal alloy material and may incorporate elements of iron,nickel, cobalt, copper, chromium, molybdenum, vanadium, tantalum,tungsten, and a combination thereof.

Suitable organic materials can include polymers, which can includethermoplastics, thermosets, elastomers, and a combination thereof.Particularly useful polymers can include polyimides, polyamides, resins,polyurethanes, polyesters, and the like. It will further be appreciatedthat the elongated body can include natural organic materials, forexample, rubber.

To facilitate processing and formation of the abrasive article, thesubstrate may be connected to a spooling mechanism. For example, thewire can be fed between a feed spool and a receiving spool. Thetranslation of the wire between the feed spool and the receiving spoolcan facilitate processing, such that for example, the wire may betranslated through desired forming processes to form the componentlayers of the finally-formed abrasive article while being translatedfrom the feed spool to the receiving spool.

In further reference to the process of providing a substrate, it will beappreciated that the substrate can be spooled from a feed spool to areceiving spool at a particular rate to facilitate processing. Forexample, the substrate can be spooled at a rate of not less than about 5m/min from the feed spool to the receiving spool. In other embodiments,the rate of spooling can be greater, such that it is at least about 8m/min, at least about 10 m/min, at least about 12 m/min, or even atleast about 14 m/min In particular instances, the spooling rate may benot greater than about 500 m/min, such as not greater than about 200m/min The rate of spooling can be within a range between any of theminimum and maximum values noted above. It will be appreciated thespooling rate can represent the rate at which the finally-formedabrasive article can be formed.

After providing a substrate at step 101, the process can continue at anoptional step 102 that includes providing a barrier layer overlying thesubstrate. According to one aspect, the barrier layer can be overlying aperipheral surface of a substrate, such that it may be in direct contactwith the peripheral surface of the substrate, and more particularly, canbe bonded directly to the peripheral surface of the substrate. In oneembodiment, the barrier layer can be bonded to the peripheral surface ofthe substrate and may define a diffusion bond region between the barrierlayer and the substrate, characterized by an interdiffusion of at leastone metal element of the substrate and one element of the barrier layer.In one particular embodiment, the barrier layer can be disposed betweenthe substrate and other overlying layers, including for example, atacking layer, a bonding layer, a coating layer, a layer of a first typeof abrasive particles, a layer of a second type of abrasive particles,and a combination thereof.

The process of providing a substrate having a barrier layer can includesourcing such a construction or fabricating such a substrate and barrierlayer construction. The barrier layer can be formed through varioustechniques, including for example, a deposition process. Some suitabledeposition processes can include, printing, spraying, dip coating, diecoating, plating (e.g., electrolyte or electroless), and a combinationthereof. In accordance with an embodiment, the process of forming thebarrier layer can include a low temperature process. For example, theprocess of forming the barrier layer can be conducted at a temperatureof not greater than about 400° C., such as not greater than about 375°C., not greater than about 350° C., not greater than about 300° C., oreven not greater than about 250° C. Furthermore, after forming thebarrier layer it will be appreciated that further processing can beundertaken including for example cleaning, drying, curing, solidifying,heat treating, and a combination thereof. The barrier layer can serve asa barrier to chemical impregnation of the core material by variouschemical species (e.g., hydrogen) in subsequent plating processes.Moreover, the barrier layer may facilitate improved mechanicaldurability.

In one embodiment, the barrier layer can be a single layer of material.The barrier layer can be in the form of a continuous coating, overlyingthe entire peripheral surface of the substrate. The barrier material caninclude an inorganic material, such as a metal or metal alloy material.Some suitable materials for use in the barrier layer can includetransition metal elements, including but not limited to tin, silver,copper, nickel, titanium, and a combination thereof. In one embodiment,the barrier layer can be a single layer of material consistingessentially of tin. In one particular instance, the barrier layer cancontain a continuous layer of tin having a purity of at least 99.99%tin. Notably, the barrier layer can be a substantially pure, non-alloyedmaterial. That is, the barrier layer can be a metal material (e.g., tin)made of a single metal material.

In other embodiments, the barrier layer can be a metal alloy. Forexample, the barrier layer can include a tin alloy, such as acomposition including a combination of tin and another metal, includingtransition metal species such as copper, silver, and the like. Somesuitable tin-based alloys can include tin-based alloys including silver,and particularly Sn96.5/Ag3.5, Sn96/Ag4, and Sn95/Ag5 alloys. Othersuitable tin-based alloys can include copper, and particularly includingSn99.3/Cu0.7 and Sn97/Cu3 alloys. Additionally, certain tin-based alloyscan include a percentage of copper and silver, including for example,Sn99/Cu0.7/Ag0.3, Sn97/Cu2.75/Ag0.25 and, Sn95.5/Ag4/Cu0.5 alloys.

In another aspect, the barrier layer can be formed from a plurality ofdiscrete layers, including for example, at least two discrete layers.For example, the barrier layer can include an inner layer and an outerlayer overlying the inner layer. According to an embodiment, the innerlayer and outer layer can be directly contacting each other, such thatthe outer layer is directly overlying the inner layer and joined at aninterface. Accordingly, the inner layer and outer layer can be joined atan interface extending along the length of the substrate.

In one embodiment, the inner layer can include any of thecharacteristics of the barrier layer described above. For example, theinner layer can include a continuous layer of material including tin,and more particularly, may consist essentially of tin. Moreover, theinner layer and outer layer can be formed of different materialsrelative to each other. That is, for example, at least one elementpresent within one of the layers can be absent within the other layer.In one particular embodiment, the outer layer can include an elementthat is not present within the inner layer.

The outer layer can include any of the characteristics of the barrierlayer described above. For example, the outer layer can be formed suchthat it includes an inorganic material, such as a metal or a metalalloy. More particularly, the outer layer can include a transition metalelement. For example, in one certain embodiment, the outer layer caninclude nickel. In another embodiment, the outer layer can be formedsuch that it consists essentially of nickel.

In certain instances, the outer layer can be formed in the same manneras the inner layer, such as a deposition process. However, it is notnecessary that the outer layer be formed in the same manner as the innerlayer. In accordance with an embodiment, the outer layer can be formedthrough a deposition process including plating, spraying, printing,dipping, die coating, deposition, and a combination thereof. In certaininstances, the outer layer of the barrier layer can be formed atrelatively low temperatures, such as temperatures not greater than about400° C., not greater than about 375° C., not greater than about 350° C.,not greater than about 300° C., or even not greater than 250° C.According to one particular process, the outer layer can be formedthough a non-plating process, such as die coating. Moreover, theprocesses used to form the outer layer may include other methodsincluding for example heating, curing, drying, and a combinationthereof. It will be appreciated that formation of the outer layer insuch a manner may facilitate limiting the impregnation of unwantedspecies within the core and/or inner layer.

In accordance with an embodiment, the inner layer of the barrier layercan be formed to have a particular average thickness suitable for actingas a chemical barrier layer. For example, the barrier layer can have anaverage thickness of at least about 0.05 microns, such as least about0.1 microns, at least about 0.2 microns, at least about 0.3 micron, oreven at least about 0.5 microns. Still, the average thickness of theinner layer may be not greater than about 8 microns, such as not greaterthan about 7 microns, not greater than about 6 microns, not greater thanabout 5 microns, or even not greater than about 4 microns. It will beappreciated that the inner layer can have an average thickness within arange between any of the minimum and maximum thicknesses noted above.

The outer layer of the barrier layer can be formed to have a particularthickness. For example, in one embodiment the average thickness of theouter layer can be at least about 0.05 microns, such as least about 0.1microns, at least about 0.2 microns, at least about 0.3 micron, or evenat least about 0.5 microns. Still, in certain embodiments, the outerlayer can have an average thickness that is not greater than about 12microns, not greater than about 10 microns, not greater than about 8microns, not greater than about 7 microns, not greater than about 6microns, not greater than about 5 microns, not greater than about 4microns, or even not greater than about 3 microns. It will beappreciated that the outer layer of the barrier layer can have anaverage thickness within a range between any of the minimum and maximumthicknesses noted above.

Notably, in at least one embodiment, the inner layer can be formed tohave a different average thickness than the average thickness of theouter layer. Such a design may facilitate improved impregnationresistance to certain chemical species while also providing suitablebonding structure for further processing. For example, in otherembodiments the inner layer can be formed to have an average thicknessthat is greater than the average thickness of the outer layer. However,in alternative embodiments, the inner layer may be formed to have anaverage thickness so that it is less than the average thickness of theouter layer.

According to one particular embodiment, the barrier layer can have athickness ratio [t_(i):t_(o)] between an average thickness of the innerlayer (t_(i)) and an average thickness of the outer layer (t_(o)) thatcan be within a range between about 3:1 and about 1:3. In otherembodiments, the thickness ratio can be within a range between about2.5:1 and about 1:2.5, such as within a range between about 2:1 andabout 1:2, within a range between about 1.8:1 and about 1:1.8, within arange between about 1.5:1 and about 1:1.5, or even within a rangebetween about 1.3:1 and about 1:1.3.

Notably, the barrier layer (including at least the inner layer and outerlayer) can be formed to have an average thickness that is not greaterthan about 10 microns. In other embodiments, the average thickness ofthe barrier layer may be less, such as not greater than about 9 microns,not greater than about 8 microns, not greater than about 7 microns, notgreater than about 6 microns, not greater than about 5 microns, or evennot greater than about 3 microns. Still, the average thickness of thebarrier layer can be at least about 0.05 microns, such as least about0.1 microns, at least about 0.2 microns, at least about 0.3 micron, oreven at least about 0.5 microns. It will be appreciated that the barrierlayer can have an average thickness within a range between any of theminimum and maximum thicknesses noted above.

Furthermore, the abrasive articles herein can form a substrate having acertain resistance to fatigue. For example, the substrates can have anaverage fatigue life of at least 300,000 cycles as measured through aRotary Beam Fatigue Test or a Hunter Fatigue Test. The test can be aMPIF Std. 56. The rotary beam fatigue test measures the number of cyclesup to wire break at designated stress (e.g. 700 MPa), i.e. constantstress or the stress under which the wire was not ruptured in a cyclicfatigue test with a number of repeating cycles of up to 10⁶ (e.g. stressrepresents fatigue strength). In other embodiments, the substrate maydemonstrate a higher fatigue life, such as least about 400,000 cycles,at least about 450,000 cycles, at least about 500,000 cycles, or even atleast about 540,000 cycles. Still, the substrate may have a fatigue lifethat is not greater than about 2,000,000 cycles.

After optionally providing a barrier layer at step 102, the process cancontinue at step 103, which includes forming a tacking layer overlying asurface of the substrate. The process of forming a tacking layer caninclude a deposition process, including for example, spraying, printing,dipping, die coating, plating, and a combination thereof. The tackinglayer can be bonded directly to the external surface of the substrate.In fact, the tacking layer can be formed such that it overlies amajority of the external surface of the substrate, and moreparticularly, can overlie essentially the entire external surface of thesubstrate.

The tacking layer may be formed such that it is bonded to the substratein a manner that it defines a bonding region. The bonding region can bedefined by an interdiffusion of elements between the tacking layer andthe substrate. It will be appreciated that formation of the bondingregion may not necessarily be formed at the moment when the tackinglayer is deposited on the surface of the substrate. For example, theformation of a bonding region between the tacking layer and thesubstrate may be formed at a later time during processing, such asduring a heat treatment process to facilitate bonding between thesubstrate and other component layers formed on the substrate.

Alternatively, the tacking layer may be formed such that it directlycontacts at least a portion of the barrier layer, such as the exteriorperipheral surface of the barrier layer. In a particular embodiment, thetacking layer can be bonded directly to the barrier layer, and moreparticularly, bonded directly to an outer layer of the barrier layer. Asnoted above, the tacking layer may be formed such that it is bonded tothe barrier layer in a manner that it defines a bonding region. Thebonding region can be defined by an interdiffusion of elements betweenthe tacking layer and the barrier layer. It will be appreciated thatformation of the bonding region may not necessarily be formed at themoment when the tacking layer is deposited on the surface of the barrierlayer. For example, the formation of a bonding region between thetacking layer and the barrier may be formed at a later time duringprocessing, such as during a heat treatment process to facilitatebonding between the substrate and other component layers formed on thesubstrate.

Yet in another embodiment, it will be appreciated that the tacking layercan be made of material suitable for use as a tacking layer and abarrier layer. For example, the tacking layer can have the samematerials and construction of the barrier layer, facilitating improvedmechanical properties of the substrate and may include a material of atacking layer in any of the embodiments herein suitable for tacking andbinding of abrasive particles for further processing. The barrier layercan be a discontinuous layer having coated regions and gaps in thebarrier layer. The tacking layer can overlie the coated regions and thegaps in the barrier layer where the underlying substrate may be exposed.

In one particular embodiment, the tacking layer can be disposed betweenthe substrate and other overlying layers, including for example, abonding layer, a coating layer, a layer of a first type of abrasiveparticles, a layer of a second type of abrasive particles, and acombination thereof. Moreover, it will be appreciated that the tackinglayer can be disposed between the barrier layer and other overlyinglayers, including for example, a bonding layer, a coating layer, a layerof a first type of abrasive particles, a layer of a second type ofabrasive particles, and a combination thereof.

In accordance with an embodiment, the tacking layer can be formed from ametal, metal alloy, metal matrix composite, and a combination thereof.In one particular embodiment, the tacking layer can be formed of amaterial including a transition metal element. For example, the tackinglayer can be a metal alloy including a transition metal element. Somesuitable transition metal elements can include, lead, silver, copper,zinc, indium, tin, titanium, molybdenum, chromium, iron, manganese,cobalt, niobium, tantalum, tungsten, palladium, platinum, gold,ruthenium, and a combination thereof. According to one particularembodiment, the tacking layer can be made of a metal alloy including tinand lead. In particular, such metal alloys of tin and lead may contain amajority content of tin as compared to lead, including but not limitedto, a tin/lead composition of at least about 60/40.

In another embodiment, the tacking layer can be made of a materialhaving a majority content of tin. In fact, in certain abrasive articles,the tacking layer may consist essentially of tin. The tin, alone or inthe solder, can have a purity of at least about 99%, such as at leastabout 99.1%, at least about 99.2%, at least about 99.3%, at least about99.4%, at least about 99.5%, at least about 99.6%, at least about 99.7%,at least about 99.8%, or even at least about 99.9%. In another aspect,the tin can have a purity of at least about 99.99%.

According to at least one embodiment, the tacking layer may be formedvia a plating process. The plating process may be an electrolyte platingprocess or an electroless plating process. In one particular instance,the tacking layer can be formed by traversing the substrate through acertain plating material, which can include a bath that can produce atacking layer comprising a matte tin layer. The matte tin layer can be aplated layer having particular features. For example, the matte tinlayer can have an organic content of not greater than about 0.5 wt % fora total weight of the plated material (i.e., the tacking layer). Organiccontent can include compositions include carbon, nitrogen, sulfur, and acombination thereof. In certain other instances, the content of organicmaterial in the matte tin layer can be not greater than about 0.3 wt %,such as not greater than about 0.1 wt %, not greater than about 0.08 wt%, or even not greater than about 0.05 wt % for the total weight of thetacking layer. According to one embodiment, the matte tin layer can beessentially free of organic brighteners and organic grain refiners.Moreover, the matte tin layer may have a purity of at least about 99.9%.

The matte tin layer may be made from a particular plating materialhaving certain features. For example, the plating material can have anorganic content of not greater than about 0.5 wt % for a total weight ofthe plated material in the bath. Organic content can includecompositions include carbon, nitrogen, sulfur, and a combinationthereof. In certain other instances, the content of organic material inthe plated material can be not greater than about 0.3 wt %, such as notgreater than about 0.1 wt %, not greater than about 0.08 wt %, or evennot greater than about 0.05 wt % for the total weight of the platingmaterial. According to one embodiment, the plating material can beessentially free of organic brighteners and organic grain refiners.Moreover, the plating material may have a purity of at least about99.9%.

Moreover, the matte tin layer may have a particular average grain sizeof tin material. For example, the matte tin layer can have an averagegrain size of at least about 0.1 microns, such as at least about 0.2microns, at least about 0.5 microns, or even at least about 1 micron.Still, in one non-limiting embodiment, the matte tin layer can have anaverage grain size of tin of not greater than about 50 microns, such asnot greater than about 25 microns, not greater than about 15 microns, oreven not greater than about 10 microns. It will be appreciated that theaverage grain size of the grains of the matte tin layer can be within arange between any of the above minimum and maximum values.

In accordance with an embodiment, the tacking layer can be a soldermaterial. It will be appreciated that a solder material may include amaterial having a particular melting point, such as not greater thanabout 450° C. Solder materials are distinct from braze materials, whichgenerally have significantly higher melting points than soldermaterials, such as greater than 450° C., and more typically, greaterthan 500° C. Furthermore, brazing materials may have differentcompositions. In accordance with an embodiment, the tacking layer of theembodiments herein may be formed of a material having a melting point ofnot greater than about 400° C., such as not greater than about 375° C.,not greater than about 350° C., not greater than about 300° C., or evennot greater than about 250° C. Still, the tacking layer may have amelting point of at least about 100° C., such as at least about 125° C.,at least about 150° C., or even at least about 175° C. It will beappreciated that the tacking layer can have a melting point within arange between any of the minimum and maximum temperatures noted above.

According to one embodiment, the tacking layer can include a samematerial as the barrier layer, such that the compositions of the barrierlayer and the tacking layer share at least one element in common In yetan alternative embodiment, the barrier layer and the tacking layer canbe entirely different materials.

According to at least one embodiment, the formation of the tacking layercan include formation of additional layers overlying the tacking layer.For example, in one embodiment, the formation of the tacking layerincludes formation of an additional layer overlying the tacking layer tofacilitate further processing. The additional layer can be overlying thesubstrate, and more particularly, in direct contact with at least aportion of the tacking layer.

The additional layer can include a flux material, which facilitatesmelting of the material of the tacking layer and further facilitatesattachment of abrasive particles on the tacking layer. The flux materialcan be in the form of a generally uniform layer overlying the tackinglayer, and more particularly, in direct contact with the tacking layer.The additional layer in the form of a flux material can comprise amajority content of flux material. In certain instances, essentially allof the additional layer can consist of the flux material.

The flux material can be in the form of a liquid or paste. According toone embodiment, the flux material can be applied to the tacking layerusing a deposition process such as spraying, dipping, painting,printing, brushing, and a combination thereof. For at least oneexemplary embodiment, the flux material can include a material such as achloride, an acid, a surfactant, a solvent, water and a combinationthereof. In one particular embodiment, the flux can includehydrochloride, zinc chloride, and a combination thereof.

After forming the tacking layer at step 103, the process can continue atstep 104 by placing abrasive particles on the tacking layer. Referenceherein to abrasive particles is reference to any one of the multipletypes of abrasive particle described herein, including for example afirst type of abrasive particle or a second type of abrasive particle.The types of abrasive particles are described in more detail herein. Insome instances, depending upon the nature of the process, the abrasiveparticles can be in direct contact with the tacking layer. Moreparticularly, the abrasive particles can be in direct contact with anadditional layer, such as a layer comprising a flux material, overlyingthe tacking layer. In fact, the additional layer of material comprisingthe flux material can have a natural viscosity and adhesivecharacteristic that facilitates holding the abrasive particles in placeduring processing, until further processes are conducted to permanentlybond the abrasive particles in place relative to the tacking layer.

Suitable methods of providing the abrasive particles on the tackinglayer, and more particularly, on the additional layer comprising theflux material, can include various deposition methods, including but notlimited to, spraying, gravity coating, dipping, die coating, dipcoating, electrostatic coating, plating, and a combination thereof.Particularly useful methods of applying the abrasive particles caninclude a spraying process, conducted to apply a substantially uniformcoating of abrasive particles onto the additional layer comprising theflux material.

In an alternative embodiment, the process of providing the abrasiveparticles can include the formation of a mixture comprising theadditional material, which may include a flux material and the abrasiveparticles. In one particular process according to an embodiment herein,the process of providing the abrasive particles can include dip coatingthe abrasive particles on the tacking film. Dip coating can includetranslating the abrasive article through a mixture or slurry comprisingat least the flux material and the abrasive particles. As such, theabrasive particles can be applied to the tacking layer and theadditional layer comprising the flux material can be formedsimultaneously.

According to one particular embodiment, the process of applying theadditional coating, which may optionally include simultaneousapplication of the abrasive particles, depending upon the components ofthe mixture, can include a die coating process. In certain instances,the abrasive article can be translated through a mixture comprising theadditional material (and optionally the abrasive particles) andtranslated through a mechanism (e.g., a die opening having controlleddimensions) to control the thickness of the additional layer.

According to an embodiment, particular aspects of the slurry and the dipcoating process may be controlled to facilitate the formation of asuitable abrasive article. For example, in one embodiment the slurry canbe a Newtonian fluid having a viscosity of at least 0.1 mPa s and nomore than 1 Pa s at a temperature of 25 ° C. and a shear rate of 1 l/s.The slurry can also be a non-Newtonian fluid having a viscosity of atleast 1 mPa s and no more than 100 Pa s, or even not greater than about10 Pa s, at the shear rate of 10 1/s as measured at a temperature of 25°C. Viscosity can be measured using a TA Instruments AR-G2 rotationalrheometer using a set up of 25 mm parallel plates, a gap ofapproximately 2 mm, shear rates of 0.1 to 10 l/s at a temperature of 25°C.

The process of providing the abrasive particles may also includecontrolling the abrasive particle concentration (e.g., the firstabrasive particle concentration, the second abrasive particleconcentration, or a combination of first and second abrasiveconcentrations). Controlling the abrasive particle concentration caninclude at least one of controlling an amount of abrasive particlesdelivered to the tacking layer, a ratio of the amount of abrasiveparticles relative to an amount of the tacking layer, a ratio of theamount of abrasive particles relative to an amount of an additionallayer comprising the flux material, a ratio of the amount of abrasiveparticles relative to the viscosity of the slurry, a position of theabrasive particles on the tacking layer, a position of the first type ofabrasive particle on the tacking layer relative to a location of asecond type of abrasive particle, a force of delivering the abrasiveparticles, and a combination thereof. In particular instances,controlling the abrasive particle concentration can include measuringthe abrasive particle concentration during forming Various methods ofmeasuring can be used including mechanical, optical, and a combinationthereof. Additionally, in certain embodiments, the process ofcontrolling the abrasive particle concentration can include measuringthe distribution of the abrasive particles on the substrate duringforming the abrasive article and adjusting the amount of the abrasiveparticles deposited on the tacking layer based on a measured value. Inan exemplary embodiment, the process of adjusting the amount of abrasiveparticles deposited on the substrate can include changing a depositionparameter based on the measured value, including for example, in thecontext of providing the abrasive particles via a spraying process,adjusting the process parameters of the spray nozzle (e.g., force ofmaterial being ejected, weight ratio of abrasive particles to othercomponents, etc.). Some suitable examples of deposition parameters caninclude weight ratio of abrasive particles to carrier material (e.g.,flux), delivery force used to apply abrasive particles, temperature,content of organics in carrier material or on substrate, atmosphericconditions of forming environment, and the like.

For at least one embodiment, the process of depositing the abrasiveparticles onto the tacking layer can include deposition, which moreparticularly can include spraying the abrasive particles onto thetacking layer. In certain processes, spraying can include using morethan one nozzle. In more particular designs, more than one nozzle fordelivery of the abrasive particles can be used, wherein the nozzles arearranged around the substrate in axis-symmetrical pattern.

Alternatively, the process of depositing the abrasive particles on thetacking layer can include translating the abrasive article having thetacking layer through a bed of abrasive particles. In certain instances,the bed can be a fluidized bed of abrasive particles.

Reference herein to abrasive particles can include reference to multipletypes of abrasive particles, including for example, a first type ofabrasive particle and a second type of abrasive particle different thanthe first type. According to at least one embodiment, the first type ofabrasive particle can be different than the second type of abrasiveparticle based on at least one particle characteristic of the groupconsisting of hardness, friability, toughness, particle shape,crystalline structure, average particle size, composition, particlecoating, grit size distribution, and a combination thereof.

The first type of abrasive particle can include a material such as anoxide, a carbide, a nitride, a boride, an oxynitride, an oxyboride,diamond, and a combination thereof. In certain embodiments, the firsttype of abrasive particle can incorporate a superabrasive material. Forexample, one suitable superabrasive material includes diamond. Inparticular instances, the first type of abrasive particle can consistessentially of diamond.

Moreover, the second type of abrasive particle can include a materialsuch as an oxide, a carbide, a nitride, a boride, an oxynitride, anoxyboride, diamond, and a combination thereof. In certain embodiments,the second type of abrasive particle can incorporate a superabrasivematerial. For example, one suitable superabrasive material includesdiamond. In particular instances, the second type of abrasive particlecan consist essentially of diamond.

In one embodiment, the first type of abrasive particle can include amaterial having a Vickers hardness of at least about 10 GPa. In otherinstances, the first type of abrasive particle can have a Vickershardness of at least about 25 GPa, such as at least about 30 GPa, atleast about 40 GPa, at least about 50 GPa, or even at least about 75GPa. Still, in at least one non-limiting embodiment, the first type ofabrasive particle can have a Vickers hardness that is not greater thanabout 200 GPa, such as not greater than about 150 GPa, or even notgreater than about 100 GPa. It will be appreciated that the first typeof abrasive particle can have a Vickers hardness within a range betweenany of the minimum and maximum values noted above.

The second type of abrasive particle can include a material having aVickers hardness of at least about 10 GPa. In other instances, thesecond type of abrasive particle can have a Vickers hardness of at leastabout 25 GPa, such as at least about 30 GPa, at least about 40 GPa, atleast about 50 GPa, or even at least about 75 GPa. Still, in at leastone non-limiting embodiment, the second type of abrasive particle canhave a Vickers hardness that is not greater than about 200 GPa, such asnot greater than about 150 GPa, or even not greater than about 100 GPa.It will be appreciated that the second type of abrasive particle canhave a Vickers hardness within a range between any of the minimum andmaximum values noted above.

In certain instances, the first type of abrasive particle can have afirst average hardness (H1) and the second type of abrasive particle canhave a second average hardness (H2) that is different than the firstaverage hardness. In some examples, the first average hardness can begreater than the second average hardness. In still other instances, thefirst average hardness can be less than the second average hardness.According to yet another embodiment, the first average hardness can besubstantially the same as the second average hardness.

For at least one aspect, the first average hardness can be at leastabout 5% different than the second average hardness based on theabsolute value of the equation ((H1−H2)/H1)×100%. In one embodiment, thefirst average hardness is at least about 10% different, at least about20% different, at least about 30% different, at least about 40%different, at least about 50% different, at least about 60% different,at least about 70% different, at least about 80% different, or even atleast about 90% different than the second average hardness. Yet, inanother non-limiting embodiment, the first average hardness may be notgreater than about 99% different, such as not greater than about 90%different, not greater than about 80% different, not greater than about70% different, not greater than about 60% different, not greater thanabout 50% different, not greater than about 40% different, not greaterthan about 30% different, not greater than about 20% different, notgreater than about 10% different than the second average hardness. Itwill be appreciated that the difference between the first averagehardness and the second average hardness can be within a range betweenany of the above minimum and maximum percentages.

In at least one embodiment, the first type of abrasive particle can havea first average particle size (P1) different than a second averageparticle size (P2) of the second type of abrasive particle. In someinstances, the first average particle size can be greater than thesecond average particle size. In still other embodiment, the firstaverage particle size can be less than the second average particle size.According to yet another embodiment, the first average particle size canbe substantially the same as the second average particle size.

For a particular embodiment, the first type of abrasive particle canhave a first average particle size (P1) and the second type of abrasiveparticle can have a second average particle size (P2), wherein the firstaverage particle size is at least about 5% different than the secondaverage particle size based on the absolute values of the equation((P1−P2)/P1)×100%. In one embodiment, the first average particle size isat least about 10% different, such as at least about 20% different, atleast about 30% different, at least about 40% different, at least about50% different, at least about 60% different, at least about 70%different, at least about 80% different, or even at least about 90%different than the second average particle size. Yet, in anothernon-limiting embodiment, the first average particle size may be notgreater than about 99% different, such as not greater than about 90%different, not greater than about 80% different, not greater than about70% different, not greater than about 60% different, not greater thanabout 50% different, not greater than about 40% different, not greaterthan about 30% different, not greater than about 20% different, notgreater than about 10% different than the second average particle size.It will be appreciated that the difference between the first averageparticle size and the second average particle size can be within a rangebetween any of the above minimum and maximum percentages.

According to at least one embodiment, the first type of abrasiveparticle can have a first average particle size of not greater thanabout 500 microns, such as not greater than about 300 microns, notgreater than about 200 microns, not greater than about 150 microns, oreven not greater than about 100 microns. Yet, in a non-limitingembodiment, the first type of abrasive particle may have a first averageparticle size of at least about 0.1 microns, such as at least about 0.5microns, at least about 1 micron, at least about 2 microns, at leastabout 5 microns, or even at least about 8 microns. It will beappreciated that the first average particle size can be within a rangebetween any of the above minimum and maximum percentages.

For certain embodiments, the second type of abrasive particle can have asecond average particle size of not greater than about 500 microns, suchas not greater than about 300 microns, not greater than about 200microns, not greater than about 150 microns, or even not greater thanabout 100 microns. Yet, in a non-limiting embodiment, the second type ofabrasive particle may have a second average particle size of at leastabout 0.1 microns, such as at least about 0.5 microns, at least about 1micron, at least about 2 microns, at least about 5 microns, or even atleast about 8 microns. It will be appreciated that the second averageparticle size can be within a range between any of the above minimum andmaximum percentages.

For a particular embodiment, the first type of abrasive particle canhave a first average friability (F1) and the second type of abrasiveparticle can have a second average friability (F2). Moreover, the firstaverage friability can be different than the second average friability,including greater than or less than the second average friability.Still, in another embodiment, the first average friability can besubstantially the same as the second average friability.

According to one embodiment, the first average friability can be atleast about 5% different than the second average friability based on theabsolute values of the equation ((F1−F2)/F1)×100%. In one embodiment,the first average friability is at least about 10% different, such as atleast about 20% different, at least about 30% different, at least about40% different, at least about 50% different, at least about 60%different, at least about 70% different, at least about 80% different,or even at least about 90% different than the second average friability.Yet, in another non-limiting embodiment, the first average friabilitymay be not greater than about 99% different, such as not greater thanabout 90% different, not greater than about 80% different, not greaterthan about 70% different, not greater than about 60% different, notgreater than about 50% different, not greater than about 40% different,not greater than about 30% different, not greater than about 20%different, not greater than about 10% different than the second averagefriability. It will be appreciated that the difference between the firstaverage friability and the second average friability can be within arange between any of the above minimum and maximum percentages.

For a particular embodiment, the first type of abrasive particle canhave a first average toughness (T1) and the second type of abrasiveparticle can have a second average toughness (T2). Moreover, the firstaverage toughness can be different than the second average toughness,including greater than or less than the second average toughness. Still,in another embodiment, the first average toughness can be substantiallythe same as the second average toughness.

According to one embodiment, the first average toughness can be at leastabout 5% different than the second average toughness based on theabsolute values of the equation ((T1−T2)/T1)x100%. In one embodiment,the first average toughness is at least about 10% different, such as atleast about 20% different, at least about 30% different, at least about40% different, at least about 50% different, at least about 60%different, at least about 70% different, at least about 80% different,or even at least about 90% different than the second average toughness.Yet, in another non-limiting embodiment, the first average toughness maybe not greater than about 99% different, such as not greater than about90% different, not greater than about 80% different, not greater thanabout 70% different, not greater than about 60% different, not greaterthan about 50% different, not greater than about 40% different, notgreater than about 30% different, not greater than about 20% different,not greater than about 10% different than the second average toughness.It will be appreciated that the difference between the first averagetoughness and the second average toughness can be within a range betweenany of the above minimum and maximum percentages.

Particular abrasive articles of the embodiments herein may utilizeparticular contents of the first type of abrasive particle and thesecond type of abrasive particle relative to each other, which mayfacilitate improved performance For example, the first type of abrasiveparticle can be present in a first content and the second type ofabrasive particle may be present in a second content. According to oneembodiment, the first content can be greater than the second content.Yet, in other instances, the second content can be greater than thefirst content. For still another embodiment, the first content can besubstantially the same as the second content.

In at least one embodiment, the first type of abrasive particle can bepresent in a first content and the second type of abrasive particle canbe present in a second content, and the relative amount of the firstcontent to the second content based upon a numerical particle count candefine a particle count ratio (FC:SC), wherein FC represents the firstparticle count content and SC represents the second particle countcontent. According to one embodiment, the particle count ratio (FC:SC)can be not greater than about 100:1, such as not greater than about50:1, not greater than about 20:1, not greater than about 10:1, notgreater than about 5:1, or even not greater than about 2:1. In oneparticular instance, the particle count ratio (FC:SC) can beapproximately 1:1, such that the first content and second content (basedon particle count) are substantially the same or essentially the same.Still, in another non-limiting embodiment, the particle count ratio(FC:SC) can be at least about 2:1, such as at least about 5:1, at leastabout 10:1, at least about 20:1, at least about 50:1, at least about100:1. It will be appreciated that the particle count ratio can bedefined by a range between any two ratios noted above.

According to another embodiment, the particle count ratio (FC:SC) can benot greater than about 1:100, such as not greater than about 1:50, notgreater than about 1:20, not greater than about 1:10, not greater thanabout 1:5, not greater than about 1:2. Still, in another non-limitingembodiment, the particle count ratio (FC:SC) can be at least about 1:2,such as at least about 1:5, at least about 1:10, at least about 1:20, atleast about 1:50, at least about 1:100. It will be appreciated that theparticle count ratio can be defined by a range between any two ratiosnoted above. For example, the particle count ratio can be between 1:1and 1:100, such as between about 1:2 and 1:100. In other instances, theparticle count ratio may between 100:1 and 1:1, or even between about100:1 and 2:1. Still, in a non-limiting embodiment, the particle countratio may be between about 100:1 and 1:100, such as between about 50:1and 1:50, such as between about 20:1 and 1:20, between about 10:1 and1:10, between about 5:1 and 1:5, or even between about 2:1 and 1:2.

The content of the first type of abrasive particle and the second typeof abrasive particle may be measured in another manner besides theparticle count. For example, the first type of abrasive particle can bemeasured by a weight percent of the first type of abrasive particle forthe total content of abrasive particles (P1wt %) and the second type ofabrasive particle can be measured by the weight percent of the secondtype of abrasive particle for the total content of abrasive particles(P2wt %). According to one embodiment, the abrasive article can have aparticle weight ratio (P1wt %:P2wt %), as defined by the relative weightpercent of the first type of abrasive particle to the weight percent ofthe second type of abrasive particle. In one particular embodiment, theparticle weight ratio can be not greater than about 100:1, such as notgreater than about 50:1, not greater than about 20:1, not greater thanabout 10:1, not greater than about 5:1, not greater than about 2:1.Still, in one instance, the particle weight ratio (P1wt %:P2wt %) can beapproximately 1:1, such that the first content and second content (basedon weight percent) are substantially the same or essentially the same.Still, in another non-limiting embodiment, the particle weight ratio(P1wt %:P2wt %) can be at least about 2:1, such as at least about 5:1,at least about 10:1, at least about 20:1, at least about 50:1, at leastabout 100:1. It will be appreciated that the particle weight ratio (P1wt%:P2wt %) can be defined by a range between any two ratios noted above.

According to another embodiment, the particle weight ratio (P1wt %:P2wt%) can be not greater than about 1:100, such as not greater than about1:50, not greater than about 1:20, not greater than about 1:10, notgreater than about 1:5, not greater than about 1:2. Still, in anothernon-limiting embodiment, the particle weight ratio (P1wt %:P2wt %) canbe at least about 1:2, such as at least about 1:5, at least about 1:10,at least about 1:20, at least about 1:50, at least about 1:100. It willbe appreciated that the particle weight ratio (P1wt %:P2wt %) can bedefined by a range between any two ratios noted above. For example, theparticle weight ratio (P1 wt %:P2wt %) can be between 1:1 and 1:100,such as between about 1:2 and 1:100. In other instances, the particleweight ratio (P1 wt %:P2 wt %) may between 100:1 and 1:1, or evenbetween about 100:1 and 2:1. Still, in a non-limiting embodiment, theparticle weight ratio (P1wt %:P2 wt %) may be between about 100:1 and1:100, such as between about 50:1 and 1:50, such as between about 20:1and 1:20, between about 10:1 and 1:10, between about 5:1 and 1:5, oreven between about 2:1 and 1:2.

The first type of abrasive particle can have a particular shape, such asa shape from the group including elongated, equiaxed, ellipsoidal, boxy,rectangular, triangular, irregular, and the like. The second type ofabrasive particle may also have a particular shape, including forexample, elongated, equiaxed, ellipsoidal, boxy, rectangular,triangular, and the like. It will be appreciated that the shape of thefirst type of abrasive particle can be different than the shape of thesecond type of abrasive particle. Alternatively, the first type ofabrasive particle can have a shape that is substantially the same as thesecond type of abrasive particle.

Moreover, in certain instances, the first type of abrasive particle canhave a first type of crystalline structure. Some exemplary crystallinestructures can include multicrystalline, monocrystalline, polygonal,cubic, hexagonal, tetrahedral, octagonal, complex carbon structure(e.g., Bucky-ball), and a combination thereof. Additionally, the secondtype of abrasive particle can have a particular crystalline structure,such as multicrystalline, monocrystalline, cubic, hexagonal,tetrahedral, octagonal, a complex carbon structure (e.g., Bucky-ball),and a combination thereof. It will be appreciated that the crystallinestructure of the first type of abrasive particle can be different thanthe crystalline structure of the second type of abrasive particle.Alternatively, the first type of abrasive particle can have acrystalline structure that is substantially the same as the second typeof abrasive particle.

For a particular embodiment, the first type of abrasive particle can bedefined by a wide grit size distribution, wherein at least 80% of thefirst type of abrasive particle has an average particle size containedwithin a range of at least about 30 microns over a range of averageparticle sizes between about 1 micron to about 100 microns.Additionally, the second type of abrasive particle may also be definedby a wide grit size distribution wherein at least 80% of the second typeof abrasive particle has an average particle size contained within arange of at least about 30 microns over a range of average particlesizes between about 1 micron to about 100 microns.

In one embodiment, the wide grit size distribution can be a bimodalparticle size distribution, wherein the bimodal particle sizedistribution comprises a first mode defining a first median particlesize (M1) and a second mode defining a second median particle size (M2)that is different than the first median particle size. According to aparticular embodiment, the first median particle size and second medianparticle size are at least 5% different based on the equation((M1−M2)/M1)x100%. In still other embodiments, the first median particlesize and the second median particle size can be at least about 10%different, such as at least about 20% different, at least about 30%different, at least about 40% different, at least about 50% different,at least about 60% different, at least about 70% different, at leastabout 80% different, or even at least about 90% different. Yet, inanother non-limiting embodiment, the first median particle size may benot greater than about 99% different, such as not greater than about 90%different, not greater than about 80% different, not greater than about70% different, not greater than about 60% different, not greater thanabout 50% different, not greater than about 40% different, not greaterthan about 30% different, not greater than about 20% different, or evennot greater than about 10% different than the second median particlesize. It will be appreciated that the difference between the firstmedian particle size and the second median particle size can be within arange between any of the above minimum and maximum percentages.

For a particular embodiment, the first type of abrasive particle caninclude an agglomerated particle. More particularly, the first type ofabrasive particle can consist essentially of an agglomerated particle.Moreover, the second type of abrasive particle may include anunagglomerated particle, and more particularly, may consist essentiallyof an unagglomerated particle. Still, it will be appreciated that thefirst and second type of abrasive particles may include an agglomeratedparticle or an unagglomerated particle. The first type of abrasiveparticle can be an agglomerated particle having a first average particlesize and the second type of abrasive particle including anunagglomerated particle having a second average particle size differentthan the first average particle size. Notably, for one embodiment, thesecond average particle size can be substantially the same as the firstaverage particle size.

According to an embodiment, an agglomerated particle can includeabrasive particles bonded to each other by a binder material. Somesuitable examples of a binder material can include an inorganicmaterial, an organic material, and a combination thereof. Moreparticularly, the binder material may be a ceramic, a metal, a glass, apolymer, a resin, and a combination thereof. In at least one embodiment,the binder material can be a metal or metal alloy, which may include oneor more transition metal elements. According to an embodiment, thebinder material can include at least one metal element from a componentlayer of the abrasive article, including for example, the barrier layer,the tacking layer, the bonding layer, the coating layer, and acombination thereof. For at least one abrasive article herein, at leasta portion of the binder material can be the same material as used in thetacking layer, and more particularly, essentially all of the bindermaterial can be the same material of the tacking layer. In yet anotheraspect, at least a portion of the binder material can be the samematerial as a bonding layer overlying the abrasive particles, and moreparticularly, essentially all of the binder material can be the same asthe bonding layer.

In a more particular embodiment, the binder can be a metal material thatincludes at least one active binding agent. The active binding agent maybe an element or composition including a nitride, a carbide, andcombination thereof. One particular exemplary active binding agent caninclude a titanium-containing composition, a chromium-containingcomposition, a nickel-containing composition, a copper-containingcomposition and a combination thereof.

In another embodiment, the binder material can include a chemical agentconfigured to chemically react with a workpiece in contact with theabrasive article to facilitate a chemical removal process on the surfaceof the workpiece while the abrasive article is also conducting amechanical removal process. Some suitable chemical agents can includeoxides, carbides, nitrides, an oxidizer, pH modifier, surfactant, and acombination thereof.

The agglomerated particle of embodiments herein can include a particularcontent of abrasive particles, a particular content of binder material,and a particular content of porosity. For example, the agglomeratedparticle can include a greater content of abrasive particle than acontent of binder material. Alternatively, the agglomerated particle caninclude a greater content of binder material than a content of abrasiveparticle. For example, in one embodiment, the agglomerated particle caninclude at least about 5 vol % abrasive particle for the total volume ofthe agglomerated particle. In other instances, the content of abrasiveparticles for the total volume of the agglomerated particle can begreater, such as at least about 10 vol %, such as at least about 20 vol%, at least about 30 vol %, at least about 40 vol %, at least about 50vol %, at least about 60 vol %, at least about 70 vol %, at least about80 vol %, or even at least about 90 vol %. Yet, in another non-limitingembodiment, the content of abrasive particles in an agglomeratedparticle for the total volume of the agglomerated particle can be notgreater than about 95 vol %, such as not greater than about 90 vol %,not greater than about 80 vol %, not greater than about 70 vol %, notgreater than about 60 vol %, not greater than about 50 vol %, notgreater than about 40 vol %, not greater than about 30 vol %, notgreater than about 20 vol %, or even not greater than about 10 vol %. Itwill be appreciated that the content of the abrasive particles in theagglomerated particle can be within a range between any of the aboveminimum and maximum percentages.

According to another aspect, the agglomerated particle can include atleast about 5 vol % binder material for the total volume of theagglomerated particle. In other instances, the content of bindermaterial for the total volume of the agglomerated particle can begreater, such as at least about 10 vol %, such as at least about 20 vol%, at least about 30 vol %, at least about 40 vol %, at least about 50vol %, at least about 60 vol %, at least about 70 vol %, at least about80 vol %, or even at least about 90 vol %. Yet, in another non-limitingembodiment, the content of binder material in an agglomerated particlefor the total volume of the agglomerated particle can be not greaterthan about 95 vol %, such as not greater than about 90 vol %, notgreater than about 80 vol %, not greater than about 70 vol %, notgreater than about 60 vol %, not greater than about 50 vol %, notgreater than about 40 vol %, not greater than about 30 vol %, notgreater than about 20 vol %, or even not greater than about 10 vol %. Itwill be appreciated that the content of the binder material in theagglomerated particle can be within a range between any of the aboveminimum and maximum percentages.

In yet another aspect, the agglomerated particle can include aparticular content of porosity. For example, the agglomerated particlecan include at least about 1 vol % porosity for the total volume of theagglomerated particle. In other instances, the content of porosity forthe total volume of the agglomerated particle can be greater, such as atleast about 5 vol %, at least about 10 vol %, at least about 20 vol %,at least about 30 vol %, at least about 40 vol %, at least about 50 vol%, at least about 60 vol %, at least about 70 vol %, or even at leastabout 80 vol %. Yet, in another non-limiting embodiment, the content ofporosity in an agglomerated particle for the total volume of theagglomerated particle can be not greater than about 90 vol %, notgreater than about 80 vol %, not greater than about 70 vol %, notgreater than about 60 vol %, not greater than about 50 vol %, notgreater than about 40 vol %, not greater than about 30 vol %, notgreater than about 20 vol %, or even not greater than about 10 vol %. Itwill be appreciated that the content of the porosity in the agglomeratedparticle can be within a range between any of the above minimum andmaximum percentages.

The porosity within the agglomerated particle can be of various types.For example, the porosity can be closed porosity, generally defined bydiscrete pores that are spaced apart from each other within the volumeof the agglomerated particle. In at least one embodiment, a majority ofthe porosity within the agglomerated particle can be closed porosity.Alternatively, the porosity can be open porosity, defining a network ofinterconnected channels extending through the volume of the agglomeratedparticle. In certain instances, a majority of the porosity can be openporosity.

The agglomerated particle can be sourced from a supplier. Alternatively,the agglomerated particle may be formed prior to the formation of theabrasive article. Suitable processes for forming the agglomeratedparticle can include screening, mixing, drying, solidifying, electrolessplating, electrolyte plating, sintering, brazing, spraying, printing,and a combination thereof.

According to one particular embodiment, the agglomerated particle can beformed in-situ with the formation of the abrasive article. For example,the agglomerated particle may be formed while forming the tacking layeror while forming a bonding layer over the tacking layer. Suitableprocesses for forming the agglomerated particle in-situ with theabrasive article can include a deposition process. Particular depositionprocesses can include, but are not limited to, plating, electroplating,dipping, spraying, printing, coating, gravity coating, and a combinationthereof. In at least one particular embodiment, the process of formingthe agglomerated particle comprises simultaneously forming a bondinglayer and the agglomerated particle via a plating process.

Still, according to another embodiment, any of the abrasive particles,including the first type or second type can be placed on the abrasivearticle during the formation of the bonding layer. The abrasiveparticles may be deposited on the tacking layer with the bonding layervia a deposition process. Some suitable exemplary deposition processescan include spraying, gravity coating, electroless plating, electrolyteplating, dipping, die coating, electrostatic coating, and a combinationthereof,

According to at least one embodiment, the first type of abrasiveparticle can have a first particle coating. Notably, the first particlecoating layer can overlie the exterior surface of the first type ofabrasive particle, and more particularly, may be in direct contact withthe exterior surface of the first type of abrasive particle. Suitablematerials for use as the first particle coating layer can include ametal or metal alloy. In accordance with one particular embodiment, thefirst particle coating layer can include a transition metal element,such as titanium, vanadium, chromium, molybdenum, iron, cobalt, nickel,copper, silver, zinc, manganese, tantalum, tungsten, and a combinationthereof. One certain first particle coating layer can include nickel,such as a nickel alloy, and even alloys having a majority content ofnickel, as measured in weight percent as compared to other speciespresent within the first particle coating layer. In more particularinstances, the first particle coating layer can include a single metalspecies. For example, the first particle coating layer can consistessentially of nickel. The first particle film layer can be a platedlayer, such that it may be an electrolyte plated layer and anelectroless plated layer.

The first particle coating layer can be formed to overlie at least aportion of the exterior surface of the first type of abrasive particle.For example, the first particle coating layer may overly at least about50% of the exterior surface area of the abrasive particle. In otherembodiments, the coverage of the first particle coating layer can begreater, such as at least about 75%, at least about 80%, at least about90%, at least about 95%, or essentially the entire exterior surface ofthe first type of abrasive particle.

The first particle coating layer may be formed to have a particularcontent relative to the amount of the first type of abrasive particle tofacilitate processing. For example, the first particle coating layer canbe at least about 5% of the total weight of each of the first type ofabrasive particle. In other instances, the relative content of the firstparticle coating layer to the total weight of each of the first type ofabrasive particle can be greater, such as at least about 10%, at leastabout 20%, at least about 30%, at least about 40%, at least about 50%,at least about 60%, at least about 70%, or even at least about 80%. Yet,in another non-limiting embodiment, the relative content of the firstparticle coating layer to the total weight of each of the first type ofabrasive particle may be not greater than about 100%, such as notgreater than about 90%, not greater than about 80%, not greater thanabout 70%, not greater than about 60%, not greater than about 50%, notgreater than about 40%, not greater than about 30%, not greater thanabout 20%, or even not greater than about 10%. It will be appreciatedthat the relative content of the first particle coating layer to thetotal weight of each of the first type of abrasive particle can bewithin a range between any of the minimum and maximum percentages notedabove.

According to one embodiment, the first particle coating layer can beformed to have a particular thickness suitable to facilitate processing.For example, the first particle coating layer can have an averagethickness of not greater than about 5 microns, such as not greater thanabout 4 microns, not greater than about 3 microns, or even not greaterthan about 2 microns. Still, according to one non-limiting embodiment,the first particle coating layer can have an average thickness of atleast about 0.01 microns, 0.05 microns, at least about 0.1 microns, oreven at least about 0.2 microns. It will be appreciated that the averagethickness of the first particle coating layer can be within a rangebetween any of the minimum and maximum values noted above.

According to certain aspects herein, the first particle coating layercan be formed of a plurality of discrete film layers. For example, thefirst particle coating layer can include a first particle film layeroverlying the first type of abrasive particle, and a second particlefilm layer different than the first particle film layer overlying thefirst particle film layer. The first particle film layer may be indirect contact with an exterior surface of the first type of abrasiveparticle and the second particle film layer may be in direct contactwith the first particle film layer.

In at least one aspect, the second particle film layer overlies at leastabout 50% of an exterior surface area of the first particle film layeron the first type of abrasive particle. In other instances, the secondparticle film overlies a greater surface area, such as at least about75%, at least about 90%, or even essentially the entire exterior surfacearea of the first particle film layer of the first type of abrasiveparticle.

The first particle film layer can include any of the materials notedherein for the first particle coating layer, including for example, ametal, a metal alloy, and a combination thereof. In some instances, thefirst particle film layer may include a transition metal element, andmore particularly, a metal such as titanium, vanadium, chromium,molybdenum, iron, cobalt, nickel, copper, silver, zinc, manganese,tantalum, tungsten, and a combination thereof. The first particle filmlayer may include a majority content of nickel, such that in someinstances, the first particle film layer consists essentially of nickel.In yet another embodiment, the first particle film layer may consistessentially of copper.

The second particle film layer can include any of the materials notedherein for the first particle coating layer, including for example, ametal, a metal alloy, metal matrix composites, and a combinationthereof. The second particle film layer may include the same material asthe first particle film layer. However, in at least one embodiment, thesecond particle film layer includes a different material, and notably,may be completely distinct in composition from the first particle filmlayer. In some instances, the second particle film layer may include atransition metal element, and more particularly, a metal such as lead,silver, copper, zinc, tin, titanium, molybdenum, chromium, iron,manganese, cobalt, niobium, tantalum, tungsten, palladium, platinum,gold, ruthenium, and a combination thereof. The second particle filmlayer may include a majority content of tin, such that in someinstances, the second particle film layer consists essentially of tin.In yet another embodiment, the second particle film layer may include ametal alloy of tin.

The second particle film layer may include a low temperature metal alloy(LTMA) material. The LTMA material can have a melting point of notgreater than about 450° C., such as not greater than about 400° C., notgreater than about 375° C., not greater than about 350° C., not greaterthan about 300° C., or even not greater than about 250° C. Still,according to at least one non-limiting embodiment, the LTMA material canhave a melting point of at least about 100° C., such as at least about125° C., or even at least about 150° C. It will be appreciated that themelting point of the LTMA material can be within a range between any ofthe minimum and maximum values noted above.

The first particle film layer can have an average thickness that isdifferent than the average thickness of the second particle film layer.For example, in some instances, the first particle film layer can havean average thickness that is greater than the average thickness of thesecond particle film layer. In yet another embodiment, the firstparticle film layer can have an average thickness less than an averagethickness of the second particle film layer. Still, in at least onenon-limiting embodiment, the first particle film layer can have anaverage thickness substantially equal to the average thickness of thesecond particle film layer.

The first particle film layer may be present in a particular relativeamount compared to the total weight of each of the first type ofabrasive particle. For example, the relative content of the firstparticle film layer to the total weight of each of the first type ofabrasive particle can be at least about 5%, such as at least about 10%,at least about 20%, at least about 30%, at least about 40%, at leastabout 50%, at least about 60%, at least about 70%, or even at leastabout 80%. Yet, in another non-limiting embodiment, the relative contentof the first particle film layer to the total weight of each of thefirst type of abrasive particle may be not greater than about 100%, suchas not greater than about 90%, not greater than about 80%, not greaterthan about 70%, not greater than about 60%, not greater than about 50%,not greater than about 40%, not greater than about 30%, not greater thanabout 20%, or even not greater than about 10%. It will be appreciatedthat the relative content of the first particle film layer to the totalweight of each of the first type of abrasive particle can be within arange between any of the minimum and maximum percentages noted above.

The second particle film layer may be present in a particular relativeamount compared to the total weight of each of the first type ofabrasive particle and the first particle film layer. For example, therelative content of the second particle film layer to the total weightof each of the first type of abrasive particle and the first particlefilm layer can be at least about 5%, such as at least about 10%, atleast about 20%, at least about 30%, at least about 40%, at least about50%, at least about 60%, at least about 70%, or even at least about 80%.Yet, in another non-limiting embodiment, the relative content of thesecond particle film layer to the total weight of each of the first typeof abrasive particle and the first particle film layer may be notgreater than about 200%, such as not greater than about 150%, notgreater than about 120%, not greater than about 100%, not greater thanabout 80%, not greater than about 60%, not greater than about 50%, notgreater than about 40%, not greater than about 30%, or even not greaterthan about 20%. It will be appreciated that the relative content of thesecond particle film layer to the total weight of each of the first typeof abrasive particle and the first particle film layer can be within arange between any of the minimum and maximum percentages noted above.

According to one embodiment, the first particle film layer can be formedto have a particular thickness suitable to facilitate processing. Forexample, the first particle film layer can have an average thickness ofnot greater than about 5 microns, such as not greater than about 4microns, not greater than about 3 microns, or even not greater thanabout 2 microns. Still, according to one non-limiting embodiment, thefirst particle film layer can have an average thickness of at leastabout 0.01 microns, 0.05 microns, at least about 0.1 microns, or even atleast about 0.2 microns. It will be appreciated that the averagethickness of the first particle film layer can be within a range betweenany of the minimum and maximum values noted above.

According to one embodiment, the second particle film layer can beformed to have a particular thickness suitable to facilitate processing.For example, the second particle film layer can have an averagethickness of not greater than about 5 microns, such as not greater thanabout 4 microns, not greater than about 3 microns, or even not greaterthan about 2 microns. Still, according to one non-limiting embodiment,the second particle film layer can have an average thickness of at leastabout 0.05 microns, 0.1 microns, at least about 0.3 microns, or even atleast about 0.5 microns. It will be appreciated that the averagethickness of the second particle film layer can be within a rangebetween any of the minimum and maximum values noted above.

In yet another aspect, the first particle film layer can be formed tohave a particular thickness relative to the first average particle sizeof the first type of abrasive particle, suitable to facilitateprocessing. For example, the first particle film layer can have anaverage thickness of not greater than about 50% of the first averageparticle size. In other embodiments, the average thickness of the firstparticle film layer relative to the first average particle size can beless, such as not greater than about 45%, not greater than about 40%,not greater than about 35%, not greater than about 30%, not greater thanabout 25%, not greater than about 20%, not greater than about 15%, notgreater than about 10%, or even not greater than about 5%. Still, in atleast one non-limiting embodiment, the average thickness of the firstparticle film layer relative to the first average particle size can beat least about 1%, at least about 5%, at least about 10%, at least about15%, at least about 20%, at least about 25%, at least about 30%, atleast about 40%, or even at least about 45%. It will be appreciated thatthe average thickness of the first particle film layer relative to thefirst average particle size can be within a range between any of theminimum and maximum percentages noted above.

According to another embodiment, the second particle film layer can beformed to have a particular thickness relative to the first averageparticle size of the first type of abrasive particle, suitable tofacilitate processing. For example, the second particle film layer canhave an average thickness of not greater than about 50% of the firstaverage particle size. In other embodiments, the average thickness ofthe second particle film layer relative to the first average particlesize can be less, such as not greater than about 45%, not greater thanabout 40%, not greater than about 35%, not greater than about 30%, notgreater than about 25%, not greater than about 20%, not greater thanabout 15%, not greater than about 10%, or even not greater than about5%. Still, in at least one non-limiting embodiment, the averagethickness of the second particle film layer relative to the firstaverage particle size can be at least about 1%, at least about 5%, atleast about 10%, at least about 15%, at least about 20%, at least about25%, at least about 30%, at least about 40%, or even at least about 45%.It will be appreciated that the average thickness of the second particlefilm layer relative to the first average particle size can be within arange between any of the minimum and maximum percentages noted above.

It will further be appreciated that the second type of abrasive particlecan include a second particle coating layer. The second particle coatinglayer can include any of the features of the first particle coatinglayer, including properties, features, and characteristics relative tothe second type of abrasive particle.

After placing the abrasive particles (e.g., the first type of abrasiveparticles, the second type of abrasive particles, and any other types)on the tacking layer at step 104, the process can continue at step 105by treating the tacking layer to bind the abrasive particles in thetacking layer. Treating may include processes such as heating, curing,drying, melting, sintering, solidification and a combination thereof. Inone particular embodiment, treating includes a thermal process, such asheating the tacking layer to a temperature sufficient to induce meltingof the tacking layer, while avoiding excessive temperatures to limitdamage to the abrasive particles and substrate. For example, treatingcan include heating the substrate, tacking layer, and abrasive particlesto a temperature of not greater than about 450° C. Notably, the processof treating can be conducted at a treating temperature that is less,such as not greater than about 375° C., not greater than about 350° C.,not greater than about 300° C., or even not greater than about 250° C.In other embodiments, the process of treating can include heating thetacking layer to a melting point of at least about 100° C., at leastabout 150° C., or even at least about 175° C.

It will be appreciated that the heating process can facilitate meltingof materials within the tacking layer and additional layers comprisingthe flux material to bond the abrasive particles to the tacking layerand the substrate. The heating process can facilitate the formation of aparticular bond between the abrasive particle and the tacking layer.Notably, in the context of coated abrasive particles, a metallic bondingregion can be formed between the particle coating material (e.g., thefirst particle coating layer and second particle coating layer) of theabrasive particles and the tacking layer material. The metallic bondingregion can be characterized by diffusion bond region having aninterdiffusion between at least one chemical species of the tackinglayer and at least one species of the particle coating layer overlyingthe abrasive particles, such that the metallic bonding region comprisesa mixture of chemical species from the two component layers.

After forming the tacking layer and applying the additional layers forfacilitate binding of the abrasive particles, the excess material of theadditional layers can be removed. For example, according to anembodiment, a cleaning process may be utilized to remove the excessadditional layers, such as residual flux material. According to oneembodiment, the cleaning process may utilize one or a combination ofwater, acids, bases, surfactants, catalysts, solvents, and a combinationthereof. In one particular embodiment, the cleaning process can be astaged process, starting with a rinse of the abrasive article using agenerally neutral material, such as water or deionized water. The watermay be room temperature or hot, having a temperature of at least about40° C. After the rinsing operation the cleaning process may include analkaline treatment, wherein the abrasive article is traversed through abath having a particular alkalinity, which may include an alkalinematerial. The alkaline treatment may be conducted at room temperature,or alternatively, at elevated temperatures. For example, the bath of thealkaline treatment may have a temperature of at least about 40° C., suchat least about 50° C., or even at least about 70° C., and not greaterthan about 200° C. The abrasive article may be rinsed after the alkalinetreatment.

After the alkaline treatment, the abrasive article may undergo anactivation treatment. The activation treatment may include traversingthe abrasive article through a bath having a particular element orcompound, including an acid, a catalyst, a solvent, a surfactant, and acombination thereof. In one particular embodiment, the activationtreatment can include an acid, such as a strong acid, and moreparticularly hydrochloric acid, sulfuric acid, and a combinationthereof. In some instances, the activation treatment can include acatalyst that may include a halide or halide-containing material. Somesuitable examples of catalysts can include potassium hydrogen fluoride,ammonium bifluoride, sodium bifluoride, and the like.

The activation treatment may be conducted at room temperature, oralternatively, at elevated temperatures. For example, the bath of theactivation treatment may have a temperature of at least about 40° C.,but not greater than about 200° C. The abrasive article may be rinsedafter the activation treatment.

According to one embodiment, after suitably cleaning the abrasivearticle, an optional process may be utilized to facilitate the formationof abrasive particles having exposed surfaces after complete formationof the abrasive article. For example, in one embodiment, an optionalprocess of selectively removing at least a portion of the particlecoating layer on the abrasive particles may be utilized. The selectiveremoval process may be conducted such that the material of the particlecoating layer is removed while other materials of the abrasive article,including for example, the tacking layer are less affected, or evenessentially unaffected. According to a particular embodiment, theprocess of selectively removing comprises etching. Some suitable etchingprocesses can include wet etching, dry etching, and a combinationthereof. In certain instances, a particular etchant may be used that isconfigured to selectively remove the material of the particle coatinglayer of the abrasive particles and leaving the tacking layer intact.Some suitable etchants can include nitric acid, sulfuric acid,hydrochloride acid, organic acid, nitric salt, sulfuric salt, chloridesalt, alkaline cyanide based solutions, and a combination thereof.

As described herein, the abrasive article can include a first type ofabrasive particle and a second type of abrasive particle different thanthe first type of abrasive particle. In certain instances, the selectiveremoval process can be conducted on only the first type of abrasiveparticle, only the second type of abrasive particle, or both the firsttype of abrasive particle and the second type of abrasive particle.Selective removal of the particle coating layer of either the first typeor second type may be facilitated by the use of a first type of abrasiveparticle having a first particle coating layer different than the secondparticle coating layer of the second type of abrasive particle.

In yet another embodiment, the formation of abrasive particles havingexposed surfaces (See, for example, FIGS. 12A and 12B) can befacilitated by the use of abrasive particles having a particle coatinglayer that is discontinuous. That is, the particle coating layer canoverlie a fraction of the total exterior surface area, such that theparticle coating layer has gaps or openings in the coating layer. Suchparticles may also facilitate the formation of abrasive particles havingexposed surfaces without the necessarily utilizing a selective removalprocess.

After treating the tacking layer at step 105, the process can continueat step 106, by forming a bonding layer over the tacking layer andabrasive particles. Formation of the bonding layer can facilitateformation of an abrasive article having improved performance, includingbut not limited to, wear resistance and particle retention. Furthermore,the bonding layer can enhance abrasive particle retention for theabrasive article. In accordance with an embodiment, the process offorming the bonding layer can include deposition of the bonding layer onthe external surface of the article defined by the abrasive particlesand the tacking layer. In fact, the bonding layer can be bonded directlyto the abrasive particles and the tacking layer.

Forming the bonding layer can include a deposition process. Somesuitable deposition processes can include plating (electrolyte orelectroless), spraying, dipping, printing, coating, and a combinationthereof. In accordance with one particular embodiment, the bonding layercan be formed by a plating process. For at least one particularembodiment, the plating process can be an electrolyte plating process.In another embodiment, the plating process can include an electrolessplating process.

The bonding layer can be formed such that it can directly contact atleast a portion of the tacking layer, a portion of the first type ofabrasive particle, a portion of the second type of abrasive particle,the particle coating layer on the first type of abrasive particle, theparticle coating layer on the second type of abrasive particle, and acombination thereof.

The bonding layer can overlie a majority of an external surface of thesubstrate and an external surface of the first type of abrasiveparticle. Moreover, in certain instances, the bonding layer can overliea majority of an external surface of the substrate and an externalsurface of the second type of abrasive particle. In certain embodiments,the bonding layer can be formed such that it overlies at least 90% ofthe exposed surfaces of the abrasive particles and tacking layer. Inother embodiments, the coverage of the bonding layer can be greater,such that it overlies at least about 92%, at least about 95%, or even atleast about 97% of the exposed surfaces of the abrasive particles andtacking layer. In one particular embodiment, the bonding layer can beformed such that it can overlie essentially all of the external surfacesof the first type of abrasive particle, the second type of abrasiveparticle, and the substrate, thus defining the exterior surface of theabrasive article.

Still, in an alternative embodiment, the bonding layer can beselectively placed, such that exposed regions can be formed on theabrasive article. Further description of a selectively formed bondinglayer with exposed surfaces of diamond are provided herein.

The bonding layer can be made of a particular material, such as anorganic material, inorganic material, and a combination thereof. Somesuitable organic materials can include polymers such as a UV curablepolymer, thermosets, thermoplastics, and a combination thereof. Someother suitable polymer materials can include urethanes, epoxies,polyimides, polyamides, acrylates, polyvinyls, and a combinationthereof.

Suitable inorganic materials for use in the bonding layer can includemetals, metal alloys, cermets, ceramics, composites, and a combinationthereof. In one particular instance, the bonding layer can be formed ofa material having at least one transition metal element, and moreparticularly a metal alloy containing a transition metal element. Somesuitable transition metal elements for use in the bonding layer caninclude lead, silver, copper, zinc, tin, titanium, molybdenum, chromium,iron, manganese, cobalt, niobium, tantalum, tungsten, palladium,platinum, gold, ruthenium, and a combination thereof. In certaininstances, the bonding layer can include nickel, and may be a metalalloy comprising nickel, or even a nickel-based alloy. In still otherembodiments, the bonding layer can consist essentially of nickel.

In accordance with one embodiment, the bonding layer can be made of amaterial, including for example, composite materials, having a hardnessthat is greater than a hardness of the tacking layer. For example, thebonding layer can have a Vickers hardness that is at least about 5%harder than a Vickers hardness of the tacking layer based on theabsolute values of the equation ((Hb−Ht)/Hb)×100%, wherein Hb representsthe hardness of the bonding layer and Ht represents the hardness of thetacking layer. In one embodiment, the bonding layer can be at leastabout 10% harder, such as at least about 20% harder, at least about 30%harder, at least about 40% harder, at least about 50% harder, at leastabout 75% harder, at least about 90% harder, or even at least about 99%harder than the hardness of the tacking layer. Yet, in anothernon-limiting embodiment, the bonding layer may be not greater than about99% harder, such as not greater than about 90% harder, not greater thanabout 80% harder, not greater than about 70% harder, not greater thanabout 60% harder, not greater than about 50% harder, not greater thanabout 40% harder, not greater than about 30% harder, not greater thanabout 20% harder, not greater than about 10% harder than the hardness ofthe tacking layer. It will be appreciated that the difference betweenthe hardness of the bonding layer and the tacking layer can be within arange between any of the above minimum and maximum percentages.

Additionally, the bonding layer can have a fracture toughness (K1c) asmeasured by indentation method, that is at least about 5% greater thanan average fracture toughness of the tacking layer based on the absolutevalues of the equation ((Tb−Tt)/Tb)×100%, wherein Tb represents thefracture toughness of the bonding layer and Tt represents the fracturetoughness of the tacking layer. In one embodiment, the bonding layer canhave a fracture toughness of at least about 8% greater, such as at leastabout 10% greater, at least about 15% greater, at least about 20%greater, at least about 25% greater, at least about 30% greater, or evenat least about 40% greater than the fracture toughness of the tackinglayer. Yet, in another non-limiting embodiment, the fracture toughnessof the bonding layer may be not greater than about 90% greater, such asnot greater than about 80% greater, not greater than about 70% greater,not greater than about 60% greater, not greater than about 50% greater,not greater than about 40% greater, not greater than about 30% greater,not greater than about 20% greater, or even not greater than about 10%greater than the fracture toughness of the tacking layer. It will beappreciated that the difference between the fracture toughness of thebonding layer and the fracture toughness of the tacking layer can bewithin a range between any of the above minimum and maximum percentages.

Optionally, the bonding layer can include a filler material. The fillercan be various materials suitable for enhancing performance propertiesof the finally-formed abrasive article. Some suitable filler materialscan include abrasive particles, pore-formers such as hollow sphere,glass spheres, bubble alumina, natural materials such as shells and/orfibers, metal particles, and a combination thereof.

In one particular embodiment, the bonding layer can include a filler inthe form of abrasive particles that may represent a third type ofabrasive particle, which can be the same as or different from the firsttype of abrasive particle and the second type of abrasive particle. Theabrasive particle filler can be significantly different than the firsttype and second type of abrasive particles, particularly with regard tosize, such that in certain instances the abrasive particle filler canhave an average particle size that is substantially less than theaverage particle size of the first type and second type of abrasiveparticles bonded to the tacking layer. For example, the abrasiveparticle filler can have an average grain size that is at least about 2times less than the average particle size of the abrasive particles. Infact, the abrasive filler may have an average particle size that is evensmaller, such as on the order of at least 3 times less, such as at leastabout 5 times less, at least about 10 times less, and particularlywithin a range between about 2 times and about 10 times less than theaverage particle size of the first type of abrasive particle, secondtype of abrasive particle, or both.

The abrasive grain filler within the bonding layer can be made from amaterial such as carbides, carbon-based materials (e.g. fullerenes),diamond, borides, nitrides, oxides, oxynitrides, oxyborides, and acombination thereof. In particular instances, the abrasive grain fillercan be a superabrasive material such as diamond, cubic boron nitride, ora combination thereof.

After forming the bonding layer at step 106, the process may optionallycontinue at step 107, with forming a coating layer overlying the bondinglayer. In particular, the coating layer may be overlying the substrate,overlying the optional barrier layer, overlying the tacking film,overlying at least a portion of the abrasive particles (e.g., first typeand/or second type of abrasive particles), and overlying at least aportion of the bonding layer, and a combination thereof. In at least oneinstance, the coating layer can be formed such that it is in directcontact with at least a portion of the bonding layer, at least a portionof the abrasive particles (e.g., first type and/or second type ofabrasive particles), and a combination thereof.

Forming of the coating layer can include a deposition process. Somesuitable deposition processes can include plating (electrolyte orelectroless), spraying, dipping, printing, coating, and a combinationthereof. In accordance with one particular embodiment, the coating layercan be formed by a plating process, and more particularly, can beelectroplated directly to an external surface of the first type ofabrasive particle and the second type of abrasive particle. In anotherembodiment, the coating layer can be formed via a dip coating process.According to yet another embodiment, the coating layer can be formed viaspraying process.

The coating layer can overlie a portion of an exterior surface area ofthe bonding layer, abrasive particles, and a combination thereof. Forexample, the coating layer can overlie at least about 25% of an exteriorsurface area of the abrasive particle and the bonding layer. In stillanother design herein, the bonding layer can overlie a majority of anexternal surface of the bonding layer. Moreover, in certain instances,the coating layer can overlie a majority of an external surface of thebonding layer and abrasive particles. In certain embodiments, thecoating layer can be formed such that it overlies at least 90% of theexposed surfaces of the abrasive particles and bonding layer. In otherembodiments, the coverage of the coating layer can be greater, such thatit overlies at least about 92%, at least about 95%, or even at leastabout 97% of the exposed surfaces of the abrasive particles and bondinglayer. In one particular embodiment, the coating layer can be formedsuch that it can overlie essentially all of the external surfaces of thefirst type of abrasive particle, the second type of abrasive particle,and the bonding layer, thus defining the exterior surface of theabrasive article.

The coating layer can include an organic material, an inorganicmaterial, and a combination thereof. According to one aspect, thecoating layer can include a material such as a metal, metal alloy,cermet, ceramic, organic, glass, and a combination thereof. Moreparticularly, the coating layer can include a transition metal element,including for example, a metal from the group of titanium, vanadium,chromium, molybdenum, iron, cobalt, nickel, copper, silver, zinc,manganese, tantalum, tungsten, and a combination thereof. For certainembodiments, the coating layer can include a majority content of nickel,and in fact, may consist essentially of nickel. Alternatively, thecoating layer can include a thermoset, a thermoplastic, and acombination thereof. In one instance, the coating layer includes a resinmaterial and may be essentially free of a solvent.

In one particular embodiment, the coating layer can include a fillermaterial, which may be a particulate material. For certain embodiments,the coating layer filler material can be in the form of abrasiveparticles, which may represent a third type of abrasive particle thatcan be the same as or different from the first type of abrasive particleand the second type of abrasive particle. Certain suitable types ofabrasive particles for use as the coating layer filler material caninclude carbides, carbon-based materials (e.g., diamond), borides,nitrides, oxides, and a combination thereof. Some alternative fillermaterials can include pore-formers such as hollow sphere, glass spheres,bubble alumina, natural materials such as shells and/or fibers, metalparticles, and a combination thereof.

The coating filler material be significantly different than the firsttype and second type of abrasive particles, particularly with regard tosize, such that in certain instances the abrasive particle fillermaterial can have an average particle size that is substantially lessthan the average particle size of the first type and second type ofabrasive particles bonded to the tacking layer. For example, the coatinglayer filler material can have an average particle size that is at leastabout 2 times less than the average particle size of the abrasiveparticles. In fact, the coating layer filler material may have anaverage particle size that is even smaller, such as on the order of atleast 3 times less, such as at least about 5 times less, at least about10 times less, and particularly within a range between about 2 times andabout 10 times less than the average particle size of the first type ofabrasive particle, second type of abrasive particle, or both.

FIG. 2A includes a cross-sectional illustration of a portion of anabrasive article in accordance with an embodiment. FIG. 2B includes across-sectional illustration of a portion of an abrasive articleincluding an optional barrier layer in accordance with an embodiment. Asillustrated, the abrasive article 200 can include a substrate 201, whichis in the form of an elongated body, such as a wire. As furtherillustrated, the abrasive article can include a tacking layer 202disposed over the entire external surface of the substrate 201.Furthermore, the abrasive article 200 can include abrasive particles 203including a coating layer 204 overlying the abrasive particles 203. Theabrasive particles 203 can be bonded to the tacking layer 202. Inparticular, the abrasive particles 203 can be bonded to the tackinglayer 202 at the interface 206, wherein a metallic bonding region can beformed as described herein.

The abrasive article 200 can include a particle coating layer 204overlying the external surfaces of the abrasive particles 203. Notably,the coating layer 204 can be in direct contact with the tacking layer202. As described herein, the abrasive particles 203, and moreparticularly, the particle coating layer 204 of the abrasive particles203, can form a metallic bonding region at the interface between thecoating layer 204 and the tacking layer 202.

According to one embodiment, the tacking layer 202 can have a particularaverage thickness as compared to the average particle size of theabrasive particles 203. It will be appreciated that reference herein toan average particle size can include reference to the first averageparticle size of the first type of abrasive particle, the second averageparticle size of the second type of abrasive particle, or a totalaverage particle size, which is an average of the first average particlesize and the second average particle size. Furthermore, to the extentthat the abrasive article includes a third type of abrasive particle,the foregoing also applies.

The tacking layer 202 can have an average thickness that is not greaterthan about 80% of the average particle size of the abrasive particles203 (i.e., the first average particle size of the first type of abrasiveparticles, the second average particle size of the second type ofabrasive particles, or the total average particle size). The relativeaverage thickness of the tacking layer to the average particle size canbe calculated by the absolute value of the equation ((Tp−Tt)/Tp)×100%,wherein Tp represents the average particle size and Tt represents theaverage thickness of the bonding layer. In other abrasive articles, thetacking layer 202 can have an average thickness of not greater thanabout 70%, such as not greater than about 60%, not greater than about50%, not greater than about 40%, not greater than about 30%, not greaterthan about 25%, or even not greater than about 20% of the averageparticle size of the abrasive particles 203. Still, in certain instancesthe average thickness of the tacking layer 202 can be at least about 2%,such as at least about 3%, such as at least about 5%, at least about 8%,at least about 10%, at least about 11%, at least about 12%, or even atleast about 13% of the average particle size of the abrasive particles203. It will be appreciated that the tacking layer 202 can have anaverage thickness within a range between any of the minimum and maximumpercentages noted above.

In alternative terms, according to certain abrasive articles, thetacking layer 202 can have an average thickness that is not greater thanabout 25 microns. In still other embodiments, the tacking layer 202 canhave an average thickness that is not greater than about 20 microns,such as not greater than about 10 microns, not greater than about 8microns, or even not greater than about 5 microns. In accordance with anembodiment, the tacking layer 202 can have an average thickness that isat least about 0.1 microns, such as at least about 0.2 microns, at leastabout 0.5 micron, or even at least about 1 micron. It will beappreciated that the tacking layer 202 can have an average thicknesswithin a range between any of the minimum and maximum values notedabove.

In particular instances, for nickel coated abrasive particles having anaverage particle size of less than about 20 microns, the averagethickness of the tacking layer can be at least about 0.5 micron.Further, the average thickness can be at least about 1.0 microns, oreven at least about 1.5 microns. The average thickness can be limited,however, such as not greater than about 5.0 microns, not greater thanabout 4.5 microns, not greater than 4.0 microns, not greater than 3.5microns, or even not greater than 3.0 microns. For abrasive particleshaving an average particle size within a range of 10 and 20 microns, thetacking layer 202 can have an average thickness within a range betweenand including any of the minimum and maximum thickness values notedabove.

Alternatively, for nickel coated abrasive particles having an averageparticle size of at least about 20 microns, and more particularly withina range of about 40-60 microns, the average thickness of the tackinglayer can be at least about 1 micron. Further, the average thickness canbe at least about 1.25 microns, at least about 1.5 microns, at leastabout 1.75 microns, at least about 2.0 microns, at least about 2.25microns, at least about 2.5 microns, or even at least about 3.0 microns.The average thickness can be limited, however, such as not greater thanabout 8.0 microns, not greater than about 7.5 microns, not greater than7.0 microns, not greater than 6.5 microns, not greater than 6.0 microns,not greater than 5.5 microns, not greater than 5.0 microns, not greaterthan 4.5 microns, or even not greater than 4.0 microns. For abrasiveparticles having an average particle size within a range of 40 and 60microns, the tacking layer 202 can have an average thickness within arange between and including any of the minimum and maximum values notedabove.

In another aspect, the abrasive article can be formed to have a ratio(C/ttl). In the ratio (C/ttl), C represents the concentration ofabrasive particles in particles per mm of substrate and ttl representsthe tacking layer thickness in percent of the average abrasive particlesize. Control of the ratio (C/ttl) can facilitate suitable formation ofabrasive articles according to the embodiments and may furtherfacilitate improved performance of the abrasive articles of theembodiments herein. In certain embodiments, the ratio C/ttl may be atleast about 2, such as, at least about 3, at least about 4, at leastabout 5, at least about 6, at least about 7, at least about 8, at leastabout 9, at least about 10, at least about 15 or even at least about 20.In still other embodiments, the ratio C/ttl may be not greater thanabout 25, such as, not greater than about 20, not greater than about 15,not greater than about 10, not greater than about 9, not greater thanabout 8, not greater than about 7, not greater than about 6, not greaterthan about 5, not greater than about 4, not greater than about 3 or evennot greater than about 2. It will be appreciated that the ratio C/ttlmay be any value within a range between any of the minimum and maximumvalues noted above.

In certain embodiments, the ratio C/ttl may be at least about 2 for aparticle concentration of at least about 10 particles per mm ofsubstrate. In other embodiments, the ratio C/ttl may be at least about 2for a particle concentration of at least about 11 particles per mm ofsubstrate, at least about 12 particles per mm substrate, or even atleast about 13 particles per mm of substrate. In one non-limitingembodiment, the ratio may be at least about 2 for a particleconcentration of not greater than about 150 particles per mm ofsubstrate, such as not greater than about 140 particles per mm ofsubstrate, not greater than about 130 particles per mm of substrate, notgreater than about 120 particles per mm of substrate. It will beappreciated that the ratio C/ttl may have a value of about 2 for aconcentration of particles within a range between any of the minimum andmaximum values noted above.

For yet another embodiment, the ratio C/ttl may be at least about 5 fora particle concentration of at least about 10 particles per mm ofsubstrate. In other embodiments, the ratio C/ttl may be at least about 5for a particle concentration of at least about 11 particles per mm ofsubstrate, at least about 12 particles per mm substrate, or even atleast about 13 particles per mm of substrate. In one non-limitingembodiment, the ratio may be at least about 5 for a particleconcentration of not greater than about 150 particles per mm ofsubstrate, such as not greater than about 140 particles per mm ofsubstrate, not greater than about 130 particles per mm of substrate, notgreater than about 120 particles per mm of substrate. It will beappreciated that the ratio C/ttl may have a value of about 5 for aconcentration of particles within a range between any of the minimum andmaximum values noted above.

For yet another embodiment, the ratio C/ttl may be at least about 8 fora particle concentration of at least about 10 particles per mm ofsubstrate. In other embodiments, the ratio C/ttl may be at least about 8for a particle concentration of at least about 11 particles per mm ofsubstrate, at least about 12 particles per mm substrate, or even atleast about 13 particles per mm of substrate. In one non-limitingembodiment, the ratio may be at least about 8 for a particleconcentration of not greater than about 150 particles per mm ofsubstrate, such as not greater than about 140 particles per mm ofsubstrate, not greater than about 130 particles per mm of substrate, notgreater than about 120 particles per mm of substrate. It will beappreciated that the ratio C/ttl may have a value of about 8 for aconcentration of particles within a range between any of the minimum andmaximum values noted above.

For yet another embodiment, the ratio C/ttl may be at least about 10 fora particle concentration of at least about 10 particles per mm ofsubstrate. In other embodiments, the ratio C/ttl may be at least about10 for a particle concentration of at least about 11 particles per mm ofsubstrate, at least about 12 particles per mm substrate, or even atleast about 13 particles per mm of substrate. In one non-limitingembodiment, the ratio may be at least about 10 for a particleconcentration of not greater than about 150 particles per mm ofsubstrate, such as not greater than about 140 particles per mm ofsubstrate, not greater than about 130 particles per mm of substrate, notgreater than about 120 particles per mm of substrate. It will beappreciated that the ratio C/ttl may have a value of at least about 10for a concentration of particles within a range between any of theminimum and maximum values noted above.

For yet another embodiment, the ratio C/ttl may be at least about 15 fora particle concentration of at least about 10 particles per mm ofsubstrate. In other embodiments, the ratio C/ttl may be at least about15 for a particle concentration of at least about 11 particles per mm ofsubstrate, at least about 12 particles per mm substrate, or even atleast about 13 particles per mm of substrate. In one non-limitingembodiment, the ratio may be at least about 15 for a particleconcentration of not greater than about 150 particles per mm ofsubstrate, such as not greater than about 140 particles per mm ofsubstrate, not greater than about 130 particles per mm of substrate, notgreater than about 120 particles per mm of substrate. It will beappreciated that the ratio C/ttl may have a value of about 15 for aconcentration of particles within a range between any of the minimum andmaximum values noted above.

For yet another embodiment, the ratio C/ttl may be at least about 20 fora particle concentration of at least about 10 particles per mm ofsubstrate. In other embodiments, the ratio C/ttl may be at least about20 for a particle concentration of at least about 11 particles per mm ofsubstrate, at least about 12 particles per mm substrate, or even atleast about 13 particles per mm of substrate. In one non-limitingembodiment, the ratio may be at least about 20 for a particleconcentration of not greater than about 150 particles per mm ofsubstrate, such as not greater than about 140 particles per mm ofsubstrate, not greater than about 130 particles per mm of substrate, notgreater than about 120 particles per mm of substrate. It will beappreciated that the ratio C/ttl may have a value of about 20 for aconcentration of particles within a range between any of the minimum andmaximum values noted above.

As further illustrated, the bonding layer 205 can be directly overlyingand directly bonded to the abrasive particles 203 and the tacking layer202. According to an embodiment, the bonding layer 205 can be formed tohave a particular thickness. For example, the bonding layer 205 can havean average thickness of at least about 5% of the average particle sizeof the abrasive particles 203 (i.e., the first average particle size ofthe first type of abrasive particles, the second average particle sizeof the second type of abrasive particles, or the total average particlesize). The relative average thickness of the bonding layer to theaverage particle size can be calculated by the absolute value of theequation ((Tp−Tb)/Tp)×100%, wherein Tp represents the average particlesize and Tb represents the average thickness of the bonding layer. Inother embodiments, the average thickness of the bonding layer 205 can begreater, such as at least about 10%, at least about 15%, at least about20%, at least about 30%, or even at least about 40%. Still, the averagethickness of the bonding layer 205 can be limited, such that it is notgreater than about 100%, not greater than about 90%, not greater thanabout 85%, or even not greater than about 80% of the average particlesize of the abrasive particles 203. It will be appreciated that thebonding layer 205 can have an average thickness within a range betweenany of the minimum and maximum percentages noted above.

In more particular instances, the bonding layer 205 can be formed tohave an average thickness that is at least 1 micron. For other abrasivearticles, the bonding layer 205 can have a greater average thickness,such as at least about 2 microns, at least about 3 microns, at leastabout 4 microns, at least about 5 microns, at least about 7 microns, oreven at least about 10 microns. Particular abrasive articles can have abonding layer 205 having an average thickness that is not greater thanabout 60 microns, such as not greater than about 50 microns, such as notgreater than about 40 microns, not greater than about 30 microns, oreven not greater than about 20 microns. It will be appreciated that thebonding layer 205 can have an average thickness within a range betweenany of the minimum and maximum values noted above.

The abrasive particles 203 can be positioned in a particular mannerrelative to other component layers of the abrasive article. For example,in at least one embodiment, a majority of the first type of abrasiveparticle can be spaced apart from the substrate. Moreover, in certaininstances, a majority of the first type of abrasive particle can bespaced apart from a barrier layer 230 of the substrate 201 (See, FIG. 2Bwhich includes an alternative illustration of a portion of an abrasivearticle according to an embodiment including a barrier layer). Moreparticularly, the abrasive article may be formed such that essentiallyall of the first type of abrasive particle is spaced apart from thebarrier layer. Additionally, it will be appreciated that a majority ofthe second type of abrasive particle can be spaced apart from thesubstrate 201 and the barrier layer 203. In fact, in certain instancesessentially all of the second type of abrasive particle is spaced apartfrom the barrier layer 203.

The abrasive article 250 illustrated in FIG. 2B includes an optionalbarrier layer, in accordance with an embodiment. As illustrated, thebarrier layer 230 can include an inner layer 231 in direct contact withthe substrate 201 and an outer layer 232 overlying the inner layer 231,and in particular, in direct contact with the inner layer 231.

FIG. 2C includes a cross-sectional illustration of a portion of anabrasive article including an optional coating layer in accordance withan embodiment. As illustrated, the abrasive article 260 can include acoating layer 235 overlying the bonding layer 205. According to aparticular embodiment, the coating layer 235 can have an averagethickness of at least about 5% of an average particle size of theabrasive particles 203 (i.e., the first average particle size of thefirst type of abrasive particles, the second average particle size ofthe second type of abrasive particles, or the total average particlesize). The relative average thickness of the coating layer to theaverage particle size can be calculated by the absolute value of theequation ((Tp−Tc)/Tp)×100%, wherein Tp represents the average particlesize and Tc represents the average thickness of the coating layer. Inother embodiments, the average thickness of the coating layer 235 can begreater, such as at least about 8%, at least about 10%, at least about15%, or even at least about 20%. Still, in another non-limitingembodiment, the average thickness of the coating layer 235 can belimited, such that it is not greater than about 50%, not greater thanabout 40%, not greater than about 30%, or even not greater than about20% of the average particle size of the abrasive particles 203. It willbe appreciated that the coating layer 235 can have an average thicknesswithin a range between any of the minimum and maximum percentages notedabove.

The coating layer 235 can have a particular average thickness relativeto the average thickness of the bonding layer 205. For example, theaverage thickness of the coating layer 235 can be less than an averagethickness of the bonding layer 205. In one particular embodiment, theaverage thickness of the coating layer 235 and the average thickness ofthe bonding layer can define a ratio (Tc:Tb) of at least about 1:2, atleast about 1:3, or even at least about 1:4. Still, in at least oneembodiment, the ratio can be not greater than about 1:20, such as notgreater than about 1:15, or even not greater than about 1:10. It will beappreciated that the ratio can be within a range between any of theupper and lower limits noted above.

According to a particular aspect, the coating layer 235 may be formed tohave an average thickness of not greater than about 15 microns, such asnot greater than about 10 microns, not greater than about 8 microns, oreven not greater than about 5 microns. Still, the average thickness ofthe coating layer 235 may be at least about 0.1 microns, such as atleast about 0.2 microns, or even at least about 0.5 microns. The coatinglayer may have an average thickness within a range between any of theminimum and maximum values noted above.

FIG. 2D includes a cross-sectional illustration of a portion of anabrasive article including a first type of abrasive particle and asecond type of abrasive particle in accordance with an embodiment. Asillustrated, the abrasive article 280 can include a first type ofabrasive particle 283 coupled to the substrate 201 and a second type ofabrasive particle 284 different than the first type of abrasive particle283 coupled to the substrate 201. The first type of abrasive particle283 can include any features described in embodiments herein, notablyincluding an agglomerated particle. The second type of abrasive particle284 can include any features described in embodiments herein, includingfor example, an unagglomerated particle. According to at least oneembodiment, the first type of abrasive particle 283 can be differentfrom the second type of abrasive particle 284 based on at least oneparticle characteristic of the group consisting of hardness, friability,toughness, particle shape, crystalline structure, average particle size,composition, particle coating, grit size distribution, and a combinationthereof.

Notably, the first type of abrasive particle 283 can be an agglomeratedparticle. FIG. 9 includes an illustration of an exemplary agglomeratedparticle according to an embodiment. The agglomerated particle 900 caninclude abrasive particles 901 contained within a binder material 903.Furthermore, as illustrated, the agglomerated particle can include acontent of porosity defined by pores 905. The pores may be presentwithin the binder material 903 between the abrasive particles 901, andin particular instances, essentially all of the porosity of theagglomerated particles can be present within the binder material 903.

According to one particular aspect, the abrasive article can be formedto have a particular abrasive particle concentration. For example, inone embodiment, the average particle size (i.e., the first averageparticle size or the second average particle size or the total averageparticle size) can be less than about 20 microns, and the abrasivearticle can have an abrasive particle concentration of at least about 10particles per mm of substrate. It will be appreciated that reference tothe particles per length is reference to the first type of abrasiveparticle, the second type of abrasive particle, or the total content ofall types of abrasive particles of the article. In yet anotherembodiment, the abrasive particle concentration can be at least about 20particles per mm of substrate, at least about 30 particles per mm ofsubstrate, at least about 60 particles per mm of substrate, at leastabout 100 particles per mm of substrate, at least about 200 particlesper mm of substrate, at least about 250 particles per mm of substrate,or even at least about 300 particles per mm of substrate. In anotheraspect, the abrasive particle concentration may be no greater than about800 particles per mm of substrate, such as no greater than about 700particles per mm of substrate, no greater than about 650 particles permm of substrate, or no greater than about 600 particles per mm ofsubstrate. It will be appreciated that the abrasive particleconcentration can be within a range between any of these above minimumand maximum values.

According to one particular aspect, the abrasive article can be formedto have a particular abrasive particle concentration. For example, inone embodiment, the average particle size (i.e., the first averageparticle size or the second average particle size or the total averageparticle size) can be at least about 20 microns, and the abrasivearticle can have an abrasive particle concentration of at least about 10particles per mm of substrate. It will be appreciated that reference tothe particles per length is reference to the first type of abrasiveparticle, the second type of abrasive particle, or the total content ofall types of abrasive particles of the article. In yet anotherembodiment, the abrasive particle concentration can be at least about 20particles per mm of substrate, at least about 30 particles per mm ofsubstrate, at least about 60 particles per mm of substrate, at leastabout 80 particles per mm of substrate, or even at least about 100particles per mm of substrate. In another aspect, the abrasive particleconcentration may be no greater than about 200 particles per mm ofsubstrate, such as no greater than about 175 particles per mm ofsubstrate, no greater than about 150 particles per mm of substrate, orno greater than about 100 particles per mm of substrate. It will beappreciated that the abrasive particle concentration can be within arange between any of these above minimum and maximum values.

In another aspect, the abrasive article can be formed to have aparticular abrasive particle concentration, measured as carats perkilometer length of the substrate. For example, in one embodiment, theaverage particle size (i.e., the first average particle size or thesecond average particle size or the total average particle size) can beless than about 20 microns, and the abrasive article can have anabrasive particle concentration of at least about 0.5 carats perkilometer of the substrate. It will be appreciated that reference to theparticles per length is reference to the first type of abrasiveparticle, the second type of abrasive particle, or the total content ofall types of abrasive particles of the article. In another embodiment,the abrasive particle concentration can be at least about 1.0 carats perkilometer of substrate, such as at least about 1.5 carats per kilometerof substrate, at least about 2.0 carats per kilometer of substrate, atleast about 3.0 carats per kilometer of substrate, at least about 4.0carats per kilometer of substrate, or even at least about 5.0 carats perkilometer of substrate. Still, in one non-limiting embodiment, theabrasive particle concentration may be not be greater than 15.0 caratsper kilometer of substrate, not greater than 14.0 carats per kilometerof substrate, not greater than 13.0 carats per kilometer of substrate,not greater than 12.0 carats per kilometer of substrate, not greaterthan 11.0 carats per kilometer of substrate, or even not greater than10.0 carats per kilometer of substrate. The abrasive particleconcentration can be within a range between any of the above minimum andmaximum values.

For yet another aspect, the abrasive article can be formed to have aparticular abrasive particle concentration, wherein the average particlesize (i.e., the first average particle size or the second averageparticle size or the total average particle size) can be at least about20 microns. In such instances, the abrasive article can have an abrasiveparticle concentration of at least about 0.5 carats per kilometer of thesubstrate. It will be appreciated that reference to the particles perlength is reference to the first type of abrasive particle, the secondtype of abrasive particle, or the total content of all types of abrasiveparticles of the article. In another embodiment, the abrasive particleconcentration can be at least about 3 carats per kilometer of substrate,such as at least about 5 carats per kilometer of substrate, at leastabout 10 carats per kilometer of substrate, at least about 15 carats perkilometer of substrate, at least about 20 carats per kilometer ofsubstrate, or even at least about 50 carats per kilometer of substrate.Still, in one non-limiting embodiment, the abrasive particleconcentration may be not be greater than 200 carats per kilometer ofsubstrate, not greater than 150 carats per kilometer of substrate, notgreater than 125 carats per kilometer of substrate, or even not greaterthan 100 carats per kilometer of substrate. The abrasive particleconcentration can be within a range between any of the above minimum andmaximum values.

For yet another aspect, the abrasive article can be formed to have aparticular tacking layer thickness, wherein the average abrasiveparticle concentration can be at least about 10 particles per mm ofsubstrate. For example, the tacking layer thickness may be at leastabout 1 microns, such as, at least about 1.5 microns, at least about 2microns, at least about 3 microns or even at least about 24 microns,wherein the average abrasive particle concentration can be at leastabout 10 particles per mm of substrate. In still other embodiments, thetacking layer thickness may be not greater than about 15 microns, notgreater than about 12 microns, not greater than about 10 microns, notgreater than about 9 microns or even not greater than about 8 microns,wherein the average abrasive particle concentration can be at leastabout 10 particles per mm of substrate. It will be appreciated that thetacking layer thickness of an abrasive article wherein the averageabrasive particle concentration can be at least about 10 particles permm of substrate, may be any value within a range between any of theminimum and maximum values noted above.

For yet another aspect, the abrasive article can be formed to have aparticular tacking layer thickness, wherein the average abrasiveparticle concentration can be at least about 100 particles per mm ofsubstrate. For example, the tacking layer thickness may be at leastabout 1 microns, such as, at least about 1.5 microns, at least about 2microns, at least about 3 microns or even at least about 4 microns,wherein the average abrasive particle concentration can be at leastabout 100 particles per mm of substrate. In still other embodiments, thetacking layer thickness may be not greater than about 15 microns, notgreater than about 12 microns, not greater than about 10 microns, notgreater than about 9 microns or even not greater than about 8 microns,wherein the average abrasive particle concentration can be at leastabout 100 particles per mm of substrate. It will be appreciated that thetacking layer thickness of an abrasive article wherein the averageabrasive particle concentration can be at least about 100 particles permm of substrate, may be any value within a range between any of theminimum and maximum values noted above.

For yet another aspect, the abrasive article can be formed to have aparticular tacking layer thickness, wherein the average abrasiveparticle concentration can be at least about 150 particles per mm ofsubstrate. For example, the tacking layer thickness may be at leastabout 1 microns, such as, at least about 1.5 microns, at least about 2microns, at least about 3 microns or even at least about 4 microns,wherein the average abrasive particle concentration can be at leastabout 150 particles per mm of substrate. In still other embodiments, thetacking layer thickness may be not greater than about 15 microns, notgreater than about 12 microns, not greater than about 10 microns, notgreater than about 9 microns or even not greater than about 8 microns,wherein the average abrasive particle concentration can be at leastabout 150 particles per mm of substrate. It will be appreciated that thetacking layer thickness of an abrasive article wherein the averageabrasive particle concentration can be at least about 150 particles permm of substrate may be any value within a range between any of theminimum and maximum values noted above.

For yet another aspect, the abrasive article can be formed to have aparticular tacking layer thickness, wherein the average abrasiveparticle concentration can be at least about 200 particles per mm ofsubstrate. For example, the tacking layer thickness may be at leastabout 1 microns, such as, at least about 1.5 microns, at least about 2microns, at least about 3 microns or even at least about 4 microns,wherein the average abrasive particle concentration can be at leastabout 200 particles per mm of substrate. In still other embodiments, thetacking layer thickness may be not greater than about 15 microns, notgreater than about 12 microns, not greater than about 10 microns, notgreater than about 9 microns or even not greater than about 8 microns,wherein the average abrasive particle concentration can be at leastabout 200 particles per mm of substrate. It will be appreciated that thetacking layer thickness of an abrasive article wherein the averageabrasive particle concentration can be at least about 200 particles permm of substrate, may be any value within a range between any of theminimum and maximum values noted above.

FIG. 10A includes a longitudinal side illustration of a portion of anabrasive article according to an embodiment. FIG. 10B includes across-sectional illustration of a portion of the abrasive article ofFIG. 10A according to an embodiment. In particular, the abrasive article1000 can include a first type of abrasive particle 283 that can define afirst layer of abrasive particles 1001. As illustrated, and according toan embodiment, the first layer of abrasive particles 1001 can define afirst pattern 1003 on the surface of the article 1000. The first pattern1003 can be defined by a relative arrangement of at least a portion(e.g., a group) of the first type of abrasive particle 283 relative toeach other. The arrangement or ordered array of the group of first typeof abrasive particles may be described relative to at least onedimensional component of the substrate 201. Dimensional components caninclude a radial component, wherein a group of the first type ofabrasive particle 283 can be arranged in an ordered array relative to aradial dimension 1081 that can define a radius or diameter (or thicknessif not circular) of the substrate 201. Another dimensional component caninclude an axial component, wherein a group of the first type ofabrasive particle 283 can be arranged in an ordered array relative to alongitudinal dimension 1080 that can define a length (or thickness ifnot circular) of the substrate 201. Yet another dimensional componentcan include a circumferential component, wherein a group of the firsttype of abrasive particle 283 can be arranged in an ordered arrayrelative to a circumferential dimension 1082 that can define acircumference (or periphery if not circular) of the substrate 201.

According to at least one embodiment, the first pattern 1003 can bedefined by a repeating axial component. As illustrated in FIG. 10A, thefirst pattern 1003 includes an ordered array of a group of the firsttype of abrasive particle 283 overlying the surface of the substrate 201that defines a repeating axial component, wherein each of the first typeof abrasive particle 283 within the group can have an ordered andpredetermined axial position relative to each other. Statedalternatively, each of the first type of abrasive particle within thegroup defining the first pattern 1003 are longitudinally spaced apartfrom each other in an ordered manner thus defining a repeating axialcomponent of the first pattern 1003. While the foregoing has describedthe first pattern 1003 as defined by a group of the first type ofabrasive particle, it will be appreciated that a pattern can be definedby a combination of different types of abrasive particles, such as anordered array of the first and second types of abrasive particles.

As further illustrated in FIG. 10A, the abrasive article 1000 caninclude a second type of abrasive particle 284 that can define a secondlayer of abrasive particles 1002. The second layer of abrasive particles1002 can be different than the first layer of abrasive particles 1001.In particular designs, the first layer of abrasive particles 1001 candefine a first radial position on the substrate 201 and the second layerof abrasive particles 1002 can define a second radial position on thesubstrate 201 that is different than the first radial position of thefirst layer of abrasive particles 1001. Moreover, according to oneembodiment, the first radial position of the first layer of abrasiveparticles 1001 and the second radial position defined by the secondlayer of abrasive particles 1002 can be radially spaced apart from eachother relative to the radial dimension 1081.

In yet another embodiment, the first layer of abrasive particles 1001can define a first axial position and the second layer of abrasiveparticles 1002 can define a second axial position spaced apart from thefirst axial position relative to the longitudinal dimension 1080.According to another embodiment, the first layer of abrasive particles1001 can define a first circumferential position and the second layer ofabrasive particles 1002 can define a second circumferential positionspaced apart from the first circumferential position relative to thecircumferential dimension 1082.

In at least one embodiment, the abrasive article 1000 can include afirst type of abrasive particle 283 that can define a first layer ofabrasive particles 1001, wherein each of the first type of abrasiveparticle 283 are substantially uniformly dispersed relative to eachother on the surface of the abrasive article. Furthermore, asillustrated, the abrasive article 1000 can include a second type ofabrasive particle 284 that can define a second layer of abrasiveparticles 100, wherein each abrasive particle of the second type ofabrasive particle 284 is substantially uniformly dispersed relative tothe other abrasive particles on the surface of the abrasive article.

As illustrated, and according to an embodiment, the first layer ofabrasive particles 1001 can be associated with a first pattern 1003 onthe surface of the article 1000 and the second layer of abrasiveparticles 1002 can be associated with a second pattern 1004 on thesurface of the article 1000. Notably, in at least one embodiment, thefirst pattern 1002 and the second pattern 1004 are different relative toeach other. According to one embodiment, the first pattern 1002 andsecond pattern 1004 can be separated from each other by a channel 1009.Moreover, depending upon the method of forming, the first pattern 1002may be associated with a first pattern of a tacking layer materialrelative to the surface of the substrate 201 (not shown) or a firstpattern of the bonding layer material relative to the surface of thesubstrate 201 (not shown). Additionally or alternatively, the secondpattern 1004 can be associated with a second pattern of a tacking layermaterial relative to the surface of the substrate 201 (not shown). Thesecond pattern of the tacking layer may be different than the firstpattern of the tacking layer. Still, in certain instances, the secondpattern of the tacking layer can be the same as the first pattern of thetacking layer. According to one embodiment, the second pattern 1004 canbe associated with a second pattern of the bonding layer relative to thesurface of the substrate 201 (not shown), which may be different thanthe first pattern of the bonding layer. Still, in at least oneembodiment, the second pattern of the bonding layer may be the same asthe first pattern of the bonding layer. The first pattern of the tackinglayer can be different than the second pattern of the tacking layer byat least a radial component, an axial component, a circumferentialcomponent, and a combination thereof. Moreover, the first pattern of thebonding layer can be different than the second pattern of the bondinglayer by at least a radial component, an axial component, acircumferential component, and a combination thereof.

As illustrated in FIG. 10A, the first pattern 1003 can be defined by atwo-dimensional shape, such as a polygonal two-dimensional shape, suchas a rectangle. Likewise, the second pattern 1004 can be defined by atwo-dimensional shape, such as a polygonal two-dimensional shape, suchas a rectangle. It will be appreciated that other two-dimensional shapesmay be employed.

According to one particular embodiment, the second pattern 1004 caninclude an ordered array of a group of the second type of abrasiveparticle 284 overlying the surface of the substrate 201 that defines arepeating axial component, wherein each of the second type of abrasiveparticle 284 within the group can have an ordered and predeterminedaxial position relative to each other. For example, each of the secondtype of abrasive particle 284 within the group defining the secondpattern 1004 can be longitudinally spaced apart from each other in anordered manner thus defining a repeating axial component of the secondpattern 1004. While the foregoing has described the second pattern 1004as defined by a group of the second type of abrasive particle, it willbe appreciated that any pattern herein can be defined by a combinationof different types of abrasive particles, such as an ordered array ofthe first and second types of abrasive particles.

As further illustrated in FIG. 10A, the abrasive article 1000 can have athird pattern 1005 that can include an ordered array of a group of thefirst type of abrasive particle 283 and the second type of abrasiveparticle 284 overlying the surface of the substrate 201 that defines arepeating radial component. Each of the first type of abrasive particle283 and second type of abrasive particle 284 within the group can havean ordered and predetermined radial position relative to each other.That is, for example, each of the first type of abrasive particle 283and second type of abrasive particle 284 within the group defining thethird pattern 1005 are radially spaced apart from each other in anordered manner thus defining a repeating radial component of the thirdpattern 1005.

In addition to the repeating radial component, the third pattern 1005can include an ordered array of a group of the first type of abrasiveparticle 283 and the second type of abrasive particle 284 overlying thesurface of the substrate 201 that defines a repeating circumferentialcomponent. As illustrated in FIG. 10A and 10B, the third pattern 1005can be defined by each of the first type of abrasive particle 283 andsecond type of abrasive particle 284 within the group having an orderedand predetermined circumferential position relative to each other. Thatis, for example, each of the first type of abrasive particle 283 andsecond type of abrasive particle 284 within the group defining the thirdpattern 1005 are circumferentially spaced apart from each other in anordered manner thus defining a repeating circumferential component ofthe third pattern 1005.

FIG. 10C includes a longitudinal side illustration of a portion of anabrasive article according to an embodiment. In particular, the abrasivearticle 1020 can include a first type of abrasive particle 283 that candefine a first layer of abrasive particles 1021. Notably, the firstlayer of abrasive particles 1021 can be arranged relative to each otherto have a repeating axial component, repeating radial component, andrepeating circumferential component. In accordance with one particularembodiment, the first layer of abrasive particles 1021 can define afirst helical path extending around the substrate 201 and defined by aplurality of turns that can be axially spaced apart from each other.According to one embodiment, a single turn includes an extension of thefirst layer of abrasive particles 1021 around the circumference of thearticle for 360 degrees. The first helical path may be continuous, oralternatively, may be defined by an axial gap, a radial gap, acircumferential gap, and a combination thereof.

Moreover, the abrasive article 1020 can include a second type ofabrasive particle 284 that can define a second layer of abrasiveparticles 1022. Notably, the second layer of abrasive particles 1022 canbe arranged relative to each other to have a repeating axial component,repeating radial component, and repeating circumferential component. Inaccordance with one particular embodiment, the second layer of abrasiveparticles 1022 can define a second helical path extending around thesubstrate 201. The second helical path can be defined by a plurality ofturns, wherein the turns can be axially spaced apart from each other,and wherein a single turn includes an extension of the second layer ofabrasive particles 1022 around the circumference of the article for 360degrees. The second helical path may be continuous, or alternatively,may be interrupted, wherein the second helical path can have an axialgap, a radial gap, a circumferential gap, and a combination thereof.

As illustrated, and according to a particular embodiment, the firstlayer of abrasive particles 1021 and second layer of abrasive particles1022 can define an intertwined helical path, wherein the first layer ofabrasive particles 1021 and second layer of abrasive particles 1022alternate in the longitudinal dimension 1080. It will be appreciatedthat a single helical path can be defined by a combination of the firsttype of abrasive particle and the second type of abrasive particle.

According to a particular embodiment, a lubricious material may beincorporated into the abrasive article to facilitate improvedperformance FIGS. 11A-11B include illustrations of various abrasivearticles having different deployments of a lubricious material accordingto embodiments herein. In at least one embodiment, the abrasive articlecan include a lubricious material overlying the substrate. In anotherinstance, the lubricious material can be overlying the tacking layer.Alternatively, the lubricious material may be in direct contact with thetacking layer, and more particularly, may be contained within thetacking layer. For one design of an embodiment, the lubricious materialcan be overlying the abrasive particles, and even may be in directcontact with the abrasive particles. In still another embodiment, thelubricious material can be overlying the bonding layer, may be at thebonding layer, and in more particular instance, in direct contact withthe bonding layer. According to one embodiment, the lubricious materialcan be contained within the bonding layer. Yet, in one alternativeembodiment, the lubricious material can be overlying a coating layer,and more particularly, can be in direct contact with the coating layer,and even more particularly, can be contained within the coating layer.The lubricious material may be formed on the exterior of the abrasivearticle, such that it is configured to make contact with a workpiece.

The lubricious material may define at least a portion of the exteriorsurface of the abrasive article. Notably, the lubricious material can bein the form of a continuous coating, such as the lubricious material1103 illustrated in FIG. 11A of the abrasive article 1100. In suchinstances, the lubricious material can overlie a majority of the surfaceof the abrasive article 1100 and define a majority of the exteriorsurface of the abrasive article 1100. According to one design of anembodiment, the lubricious material can define essentially the entireexterior surface of the abrasive article 1100.

According to another embodiment, the lubricious material may define anon-continuous layer, wherein the lubricious material overlies thesubstrate and defines a fraction of the exterior surface of the abrasivearticle. The non-continuous layer may be defined by a plurality of gapsextending between portions of the lubricious material, wherein the gapsdefine regions absent the lubricious material.

According to one embodiment, the lubricious material can be in the formof discrete particles comprising a lubricious material. The discreteparticles including the lubricious material may consist essentially ofthe lubricious material. More particularly, the discrete particles canbe disposed at various places within the abrasive article, including butnot limited to, in direct contact with the bonding layer, at leastpartially contained within the bonding layer, contained entirely withinthe bonding layer, at least partially contained within the coatinglayer, in direct contact with a coating layer and a combination thereof.For example, as illustrated in FIG. 11B, the lubricious material 1103 ispresent as discrete particles contained in the bonding layer 205.

For at least one embodiment, the lubricious material can be an organicmaterial, an inorganic material, a natural material, a syntheticmaterial, and a combination thereof. In one particular instance, thelubricious material can include a polymer, such as a fluoropolymer. Oneparticularly suitable polymer material can includepolytetrafluoroethylene (PTFE). In at least one embodiment, thelubricious material can consist essentially of PTFE.

Various methods of providing the lubricious material to the abrasivearticle may be utilized. For example, the process of providing thelubricious material may be conducted via a depositing process. Exemplarydeposition processes can include spraying, printing, plating, coating,gravity coating, dipping, die coating, electrostatic coating, and acombination thereof.

Additionally, the process of providing the lubricious material may beconducted at different times during processing. For example, providingthe lubricious material can be conducted simultaneously with forming thetacking layer. Alternatively, providing the lubricious material can beconducted simultaneously with providing the abrasive particles. In yetanother embodiment, providing the lubricious material can be completedsimultaneously with providing the bonding layer. Moreover, in oneoptional process, providing the lubricious material can be conductedsimultaneously with providing a coating layer overlying the bondinglayer.

Still, the process of providing the lubricious material can be conductedafter completing certain processes. For example, providing thelubricious material can be conducted after forming the tacking layer,after providing the abrasive particles, after providing the bondinglayer, or even after providing a coating layer.

Alternatively, it may be suitable to provide the lubricious materialprior to forming certain layers. For example, providing the lubriciousmaterial can be conducted before forming the tacking layer, beforeproviding the abrasive particles, before providing the bonding layer, oreven before providing a coating layer.

Certain articles according to embodiments herein can be processedaccording to a particular method to facilitate the formation of abrasiveparticles having an exposed surface. FIG. 12A includes an illustrationof an abrasive article including an abrasive particle having an exposedsurface. As illustrated in FIG. 12A, the abrasive article can be formedsuch that an abrasive particle 203 (e.g., first type or second type ofabrasive particle) can have an exposed surface 1201. According to anembodiment, the abrasive particle 203 can have a particle coating 1205overlying a surface of the abrasive particle 203, and preferentiallydisposed proximate to a lower surface 1204 of the abrasive particle 203.In particular, the particle coating layer 1205 can be a non-continuouscoating that is preferentially disposed at a lower surface 1204 of theabrasive particle 203 adjacent the substrate 201 and tacking layer 202.Notably, the particle coating layer 1205 may not necessarily extend overan upper surface 1203 of the abrasive particle 203, which is spaced at agreater distance from the substrate 201 than the lower surface 1204, andfacilitate the formation of the exposed surface 1201. The particlecoating layer 1205 may be removed from the upper surface 1203 of theabrasive particle via a selective removal process prior to forming thebonding layer as described in embodiments herein. The absence of a theparticle coating layer 1205 at the upper surface 1203 can facilitate theformation of an exposed surface 1201, since the bonding layer materialmay not necessarily wet the upper surface 1203 of the abrasive particle203 during forming

According to one embodiment, the exposed surface 1201 can be essentiallyabsent a metal material. In particular, the exposed surface 1201 canconsist essentially of the abrasive particle 203 and have no overlyinglayers. In certain instances, the exposed surface 1201 can consistessentially of diamond.

FIG. 12B includes a picture of an abrasive article according to anembodiment including abrasive particles having exposed surfaces. Theexposed surfaces 1201 can exist for at least about 5% of an amount ofabrasive particles of the abrasive article. It will be appreciated thatthe amount of abrasive particles can be a total amount of only the firsttype of abrasive particles, a total amount of only the second type ofabrasive particles, or a total amount of all types of abrasive particlespresent in the abrasive article. In other instances, the content ofabrasive particles having an exposed surface can be at least about 10%,such as at least about 20%, at least about 30%, at least about 40%, atleast about 50%, at least about 60%, at least about 70%, at least about80%, or even at least about 90%. Still, in a non-limiting embodiment,not greater than about 99%, such as not greater than about 98%, notgreater than about 95%, not greater than about 80%, such as not greaterthan about 70%, not greater than about 60%, not greater than about 505,not greater than about 40%, not greater than about 30%, not greater thanabout 25%, or even not greater than about 20% of an amount of theabrasive particles have an exposed surface. It will be appreciated thatthe amount of abrasive particles having an exposed surface can be withina range between any of the above noted minimum and maximum percentages.

The bonding layer may have a particular contour at the exposed surface1201. As illustrated in FIG. 12B, the bonding layer 205 can have ascalloped edge 1205 at an interface between the bonding layer 205 and anexposed surface 1201 of the abrasive particles. The scalloped edge mayfacilitate improved material removal and improved abrasive particleretention.

Certain processing techniques can facilitate use of different types ofabrasive particles having different exposed surfaces. For example, theabrasive article can include a first type of abrasive particle and asecond type of abrasive particle, wherein essentially none of the totalcontent of the second type of abrasive particle has an exposed surfacewhile at least a portion of the total content of the first type ofabrasive particle has an exposed surface. Still, in other instances, atleast a portion of a total amount of the second type of abrasiveparticle can have an exposed surface. Moreover, in one particularembodiment, the amount of the second type of abrasive particle having anexposed surface is less than the amount of the first type of abrasiveparticle having an exposed surface. Alternatively, the amount of thesecond type of abrasive particle having an exposed surface is greaterthan the amount of the first type of abrasive particle having an exposedsurface. Yet, according to another embodiment, the total amount of thesecond type of abrasive particle having an exposed surface issubstantially the same as the amount of the first type of abrasiveparticle having an exposed surface.

The abrasive articles of the embodiments herein may be wire saws thatare particularly suited for slicing of workpieces. The workpieces can bevarious materials, including but not limited to, ceramic, semiconductivematerial, insulating material, glass, natural materials (e.g., stone),organic material, and a combination thereof. More particularly, theworkpieces can include oxides, carbides, nitrides, minerals, rocks,single crystalline materials, multicrystalline materials, and acombination thereof. For at least one embodiment, an abrasive article ofan embodiment herein may be suitable for slicing a workpiece ofsapphire, quartz, silicon carbide, and a combination thereof.

According to at least one aspect, the abrasive articles of theembodiments can be used on particular machines, and may be used atparticular operating conditions that have improved and unexpectedresults compared to conventional articles. While not wishing to be boundto a particular theory, it is thought there may be some synergisticeffect between the features of the embodiments.

Generally, cutting, slicing, bricking, squaring, or any other operationcan be conducted by moving the abrasive article (i.e., wire saw) and theworkpiece relative to each other. Various types and orientations of theabrasive articles relative to the workpieces may be utilized, such thata workpiece is sectioned into wafers, bricks, rectangular bars,prismatic sections, and the like.

This may be accomplished using a reel-to-reel machine, wherein movingcomprises reciprocating the wire saw between a first position and asecond position. In certain instances, moving the abrasive articlebetween a first position and a second position comprises moving theabrasive article back and forth along a linear pathway. While the wireis being reciprocated, the workpiece may also be moved, including forexample, rotating the workpiece. FIG. 15 includes an illustration of areel-to-reel machine using an abrasive article to slice a workpiece.

Alternatively, an oscillating machine may be utilized with any abrasivearticle according to the embodiments herein. Use of an oscillatingmachine can include moving the abrasive article relative to theworkpiece between a first position and second position. The workpiecemay be moved, such as rotated, and moreover the workpiece and wire canboth be moved at the same time relative each other. An oscillatingmachine may utilize a back and forth motion of the wire guide relativeto the workpiece, wherein a reel-to-reel machine does not necessarilyutilize such a motion. FIG. 16 includes an illustration of anoscillation machine using an abrasive article to slice a workpiece.

For some applications, during the slicing operation the process mayfurther include providing a coolant at an interface of the wire saw andworkpiece. Some suitable coolants include water-based materials,oil-based materials, synthetic materials, and a combination thereof.

In certain instances, slicing can be conducted as a variable rateoperation. The variable rate operation can include moving the wire andworkpiece relative to each other for a first cycle and moving the wireand workpiece relative to each other for a second cycle. Notably, thefirst cycle and the second cycle may be the same or different. Forexample, the first cycle can include translation of the abrasive articlefrom a first position to a second position, which in particular, mayinclude translation of the abrasive article through a forward andreverse direction cycle. The second cycle can include translation of theabrasive article from a third position to a fourth position, which mayalso include translation of the abrasive article through a forward andreverse direction cycle. The first position of the first cycle can bethe same as the third position of the second cycle, or alternatively,the first position and the third position may be different. The secondposition of the first cycle can be the same as the fourth position ofthe second cycle, or alternatively, the second position and the fourthposition may be different.

According to a particular embodiment, the use of an abrasive article ofan embodiment herein in a variable rate cycle operation can include afirst cycle that includes the elapsed time to translate the abrasivearticle from a starting position in a first direction (e.g., forward) toa temporary position, and in a second direction (e.g., backward) fromthe temporary position, thus returning to the same starting position orclose to the starting position. Such a cycle can include the durationfor accelerating the wire from 0 m/s to set wire speed in the forwarddirection, the elapsed time for moving the wire at set wire speed in theforward direction, the elapsed time on decelerating the wire from setwire speed to 0 m/s in the forward direction, the elapsed time onaccelerating the wire from 0 m/s to set wire speed in the backwarddirection, the elapsed time on moving the wire at set wire speed in thebackward direction, and the elapsed time on decelerating the wire fromset wire speed to 0 m/s in the backward direction. FIG. 17 includes anexemplary plot of wire speed versus time for a single cycle of avariable rate cycle operation.

According to one particular embodiment, the first cycle can be at leastabout 30 seconds, such as at least about 60 seconds, or even t leastabout 90 seconds. Still, in one non-limiting embodiment, the first cyclecan be not greater than about 10 minutes. It will be appreciated thatthe first cycle can have a duration within a range between any of theminimum and maximum values above.

In yet another embodiment, the second cycle can be at least about 30seconds, such as at least about 60 seconds, or even at least about 90seconds. Still, in one non-limiting embodiment, the second cycle can benot greater than about 10 minutes. It will be appreciated that thesecond cycle can have a duration within a range between any of theminimum and maximum values above.

The total number of cycles in a for a cutting process may vary, but canbe at least about 20 cycles, at least about 30 cycles, or even at leastabout 50 cycles. In particular instances, the number of cycles may benot greater than about 3000 cycles or even not greater than about 2000cycles. The cutting operation may last for a duration of at least about1 hour or even at least about 2 hours. Still, depending upon theoperation, the cutting process may be longer, such as at least about 10hours, or even 20 hours of continuous cutting.

In certain cutting operations, the wire saw of any embodiment herein maybe particularly suited for operation at a particular feed rate. Forexample, the slicing operation can be conducted at a feed rate of atleast about 0.05 mm/min, at least about 0.1 mm/min, at least about 0 5mm/min, at least about 1 mm/min, or even at least about 2 mm/min. Still,in one non-limiting embodiment, the feed rate may be not greater thanabout 20 mm/min. It will be appreciated that the feed rate can be withina range between any of the minimum and maximum values above.

For at least one cutting operation, the wire saw of any embodimentherein may be particularly suited for operation at a particular wiretension. For example, the slicing operation can be conducted at a wiretension of at least about 30% of a wire break load, such as at leastabout 50% of the wire break load, or even at least about 60% of a breakload. Still, in one non-limiting embodiment, the wire tension may be notgreater than about 98% of the break load. It will be appreciated thatthe wire tension can be within a range between any of the minimum andmaximum percentages above.

According to another cutting operation, the abrasive article can have aVWSR range that facilitates improved performance VWSR is the variablewire speed ratio and can generally be described by the equationt2/(t1+t3), wherein t2 is the elapsed time when the abrasive wire movesforward or backward at a set wire speed, wherein t1 is the elapsed timewhen the abrasive wire moves forward or backward from 0 wire speed toset wire speed, and t3 is the elapsed time when the abrasive wire movesforward or backward from constant wire speed to 0 wire speed. See, forexample FIG. 17. For example, the VWSR range of a wire saw according toan embodiment herein can be at least about 1, at least about 2, at leastabout 4, or even at least about 8. Still, in one non-limitingembodiment, the VWSR rate may be not greater than about 75 or even notgreater than about 20. It will be appreciated that the VWSR rate can bewithin a range between any of the minimum and maximum values above. Inone embodiment, an exemplary machine for variable wire speed ratiocutting operations can be a Meyer Burger DS265 DW Wire Saw machine.

Certain slicing operations may be conducted on workpieces includingsilicon, which can be single crystal silicon or multicrystallinesilicon. According to one embodiment, use of an abrasive articleaccording to an embodiment demonstrates a life of at least about 8m²/km, such as at least about 10 m²/km, at least about 12 m²/km, or evenat least about 15 m²/km The wire life can be based upon the wafer areagenerated per kilometer of abrasive wire used, wherein wafer areagenerated is calculated based on one side of the wafer surface. In suchinstances, the abrasive article may have a particular abrasive particleconcentration, such as at least about 0.5 carats per kilometer of thesubstrate, at least about 1.0 carats per kilometer of substrate, atleast about 1.5 carats per kilometer of substrate, or even at leastabout 2.0 carats per kilometer of substrate. Still, the concentrationmay be not greater than about 20 carats per kilometer of substrate, oreven not greater than about 10 carats per kilometer of substrate. Theaverage particle size of the abrasive particles can be less than about20 microns. It will be appreciated that the abrasive particleconcentration can be within a range between any of the minimum andmaximum values above. The slicing operation may be conducted at a feedrate as disclosed herein.

According to another operation, a silicon workpiece including singlecrystal silicon or multicrystalline silicon can be sliced with anabrasive article according to one embodiment, and the abrasive articlecan have a life of at least about 0.5 m²/km, such as at least about 1m²/km, or even at least about 1.5 m²/km In such instances, the abrasivearticle may have a particular abrasive particle concentration, such asat least about 5 carats per kilometer of the substrate, at least about10 carats per kilometer of substrate, of at least about 20 carats perkilometer of substrate, at least about 40 carats per kilometer ofsubstrate. Still, the concentration may be not greater than about 300carats per kilometer of substrate, or even not greater than about 150carats per kilometer of substrate. The average particle size of theabrasive particles can be less than about 20 microns. It will beappreciated that the abrasive particle concentration can be within arange between any of the minimum and maximum values above.

The slicing operation may be conducted at a feed rate of at least about1 mm/min, at least about 2 mm/min, at least about 3 mm/min, at leastabout 5 mm/min. Still, in one non-limiting embodiment, the feed rate maybe not greater than about 20 mm/min. It will be appreciated that thefeed rate can be within a range between any of the minimum and maximumvalues above.

According to another operation, a sapphire workpiece can be sliced usingan abrasive article of an embodiment herein. The sapphire workpiece mayinclude a c-plane sapphire, an a-plane sapphire, or a r-plane sapphirematerial. For at least one embodiment, the abrasive article can slicethrough the sapphire workpiece and exhibit a life of at least about 0.1m²/km, such as at least about 0.2 m²/km, at least about 0.3 m²/km, atleast about 0.4 m²/km, or even at least about 0.5 m²/km In suchinstances, the abrasive article may have a particular abrasive particleconcentration, such as at least about 5 carats per kilometer of thesubstrate, at least about 10 carats per kilometer of substrate, of atleast about 20 carats per kilometer of substrate, at least about 40carats per kilometer of substrate. Still, the concentration may be notgreater than about 300 carats per kilometer of substrate, or even notgreater than about 150 carats per kilometer of substrate. The averageparticle size of the abrasive particles can be greater than about 20microns. It will be appreciated that the abrasive particle concentrationcan be within a range between any of the minimum and maximum valuesabove.

The foregoing slicing operation on the workpiece of sapphire may beconducted at a feed rate of at least about 0.05 mm/min, such as at leastabout 0.1 mm/min, or even at least about 0.15 mm/min. Still, in onenon-limiting embodiment, the feed rate may be not greater than about 2mm/min. It will be appreciated that the feed rate can be within a rangebetween any of the minimum and maximum values above.

In yet another aspect, the abrasive article may be used to slice throughworkpieces including silicon carbide, including single crystal siliconcarbide. For at least one embodiment, the abrasive article can slicethrough the silicon carbide workpiece and exhibit a life of at leastabout 0.1 m²/km, such as at least about 0.2 m²/km, at least about 0.3m²/km, at least about 0.4 m²/km, or even at least about 0.5 m²/km Insuch instances, the abrasive article may have a particular abrasiveparticle concentration, such as at least about 5 carats per kilometer ofthe substrate, at least about 10 carats per kilometer of substrate, ofat least about 20 carats per kilometer of substrate, at least about 40carats per kilometer of substrate. Still, the concentration may be notgreater than about 300 carats per kilometer of substrate, or even notgreater than about 150 carats per kilometer of substrate. It will beappreciated that the abrasive particle concentration can be within arange between any of the minimum and maximum values above.

The foregoing slicing operation on the workpiece of silicon carbide maybe conducted at a feed rate of at least about 0.05 mm/min, such as atleast about 0.10 mm/min, or even at least about 0.15 mm/min. Still, inone non-limiting embodiment, the feed rate may be not greater than about2 mm/min. It will be appreciated that the feed rate can be within arange between any of the minimum and maximum values above.

According to yet another embodiment, abrasive articles according toembodiments described herein may be produced at a certain productionrate. The production rate of embodiments of abrasive articles describedherein may be the speed of formation of an abrasive article, in metersof substrate per minute, wherein the abrasive article includes asubstrate having an elongated body, a tacking layer overlying thesubstrate, abrasive particle overlying the tacking layer and defining afirst abrasive particle concentration at least about 10 particles per mmof substrate, and the formation of the bonding layer. In certainembodiments, the production rate may be at least about 10 meters perminute, such as, at least about 12 meters per minute, at least about 14meters per minute, at least about 16 meters per minute, at least about18 meters per minute, at least about 20 meters per minute, at leastabout 25 meters per minute, at least about 30 meters per minute, atleast about 40 meters per minute or even at least about 60 meters perminute.

In particular instances, it is noted that the present method can be usedto facilitate efficient production of abrasive wire saws having a highconcentration of abrasive particles. For example, the abrasive articlesof the embodiments herein having any of the featured abrasive particleconcentrations can be formed at any of the foregoing production rateswhile maintaining or exceeding performance parameters of the industry.Without wishing to be tied to a particular theory, it is theorized thatutilization of a separate tacking process and bonding process canfacilitate improved production rates over single step attaching andbonding processes, such as conventional electroplating processes.

Abrasive articles of the embodiments herein have demonstrated improvedabrasive particle retention during use as compared to conventionalabrasive wire saws without at least one of the features of theembodiments herein. For example, the abrasive articles have an abrasiveparticle retention of at least about 2% improvement over one or moreconventional samples. In still other instances, the abrasive particleretention improvement can be at least about 4%, at least about 6%, atleast about 8%, at least about 10%, at least about 12%, at least about14%, at least about 16%, at least about 18%, at least about 20%, atleast about 24%, at least about 28%, at least about 30%, at least about34%, at least about 38%, at least about 40%, at least about 44%, atleast about 48%, or even at least about 50%. Still, in one non-limitingembodiment, the abrasive particle retention improvement can be notgreater than about 100%, such as not greater than about 95%, not greaterthan about 90%, or even not greater than about 80%.

Abrasive articles of the embodiments herein have demonstrated improvedabrasive particle retention and further demonstrated improved useablelife compared to conventional abrasive wire saws without at least one ofthe features of the embodiments herein. For example, the abrasivearticles herein can have an improvement of useable life of at leastabout 2% compared to one or more conventional samples. In still otherinstances, the increase in useable life of an abrasive article of anembodiment herein compared to a conventional article can be at leastabout 4%, at least about 6%, at least about 8%, at least about 10%, atleast about 12%, at least about 14%, at least about 16%, at least about18%, at least about 20%, at least about 24%, at least about 28%, atleast about 30%, at least about 34%, at least about 38%, at least about40%, at least about 44%, at least about 48%, or even at least about 50%.Still, in one non-limiting embodiment, the useable life improvement canbe not greater than about 100%, such as not greater than about 95%, notgreater than about 90%, or even not greater than about 80%.

EXAMPLE 1

A length of high strength carbon steel wire is obtained as a substrate.The high strength carbon steel wire has an average diameter ofapproximately 125 microns. A tacking layer is formed on the externalsurface of the substrate via electroplating. The electroplating processforms a tacking layer having an average thickness of approximately 4microns. The tacking layer is formed of a 60/40 tin/lead solderingcomposition.

After forming the tacking layer, the wire is spooled into a bathcontaining a liquid flux material commercially available as Stay Clean®Liquid Soldering Flux from Harris Products Group and the treated wire isthen sprayed with nickel-coated diamond abrasive particles having anaverage particle size of between 20 to 30 microns. Thereafter, thesubstrate, tacking layer, and abrasive particles are heat treated to atemperature to approximately 190° C. The abrasive pre-form is thencooled and rinsed. The process of bonding the nickel coated diamond tothe tacking layer is conducted at an average spooling rate of 15 m/min.

Thereafter, the abrasive pre-form is washed using 15% HCl followed by arinse with de-ionized water. The rinsed article is electroplated withnickel to form a bonding layer directly contacting and overlying theabrasive particles and tacking layer. FIG. 3 includes a magnified imageof a portion of the abrasive article formed from the process of Example1.

EXAMPLE 2

A length of high strength carbon steel wire is obtained as a substrate.The high strength carbon steel wire has an average diameter ofapproximately 125 microns. A tacking layer is formed on the externalsurface of the substrate via electroplating. The electroplating processforms a tacking layer having an average thickness of approximately 6microns. The tacking layer is formed of a 60/40 tin/lead solderingcomposition.

After forming the tacking layer, the wire is spooled into a bathcontaining a liquid flux material commercially available as Stay Clean®Liquid Soldering Flux from Harris Products Group and the treated wire isthen sprayed with nickel-coated diamond abrasive particles having anaverage particle size of between 15 to 25 microns. Thereafter, thesubstrate, tacking layer, and abrasive particles are heat treated to atemperature to approximately 190° C. The abrasive pre-form is thencooled and rinsed. The process of bonding the nickel coated diamond tothe tacking layer is conducted at an average spooling rate of 15 m/min.

Thereafter, the abrasive pre-form is washed using 15% HCl followed by arinse with de-ionized water. The rinsed article is electroplated withnickel to form a bonding layer directly contacting and overlying theabrasive particles and tacking layer. FIG. 4 illustrates the resultingarticle. As indicated in FIG. 4, the tin/lead tacking layer 402 having athickness of approximately 6 microns allows the Ni coated diamond 404 tobe relatively deeply embedded in the tacking layer 402 on the wire 406.However, after the final layer of nickel 408 is electroplated onto theNi coated diamond 404 and the tacking layer 402, the Ni coated diamond404 exhibits poor protrusion from the surface of the wire 406 and is notuseful for cutting.

EXAMPLE 3

A length of high strength carbon steel wire is obtained as a substrate.The high strength carbon steel wire has an average diameter ofapproximately 120 microns. A tacking layer is formed on the externalsurface of the substrate via electroplating. The electroplating processforms a tacking layer having an average thickness of approximately 2microns. The tacking layer is formed of a high purity tin composition(99.9% pure tin).

After forming the tacking layer, the wire is spooled into a bathcontaining a liquid flux material commercially available as Stay Clean®Liquid Soldering Flux from Harris Products Group and the treated wire isthen sprayed with nickel-coated diamond abrasive particles having anaverage particle size of between 10 to 20 microns. Thereafter, thesubstrate, tacking layer, and abrasive particles are heat treated to atemperature to approximately 250° C. The abrasive pre-form is thencooled and rinsed. The process of bonding the nickel coated diamond tothe tacking layer is conducted at an average spooling rate of 15 m/min.

Thereafter, the abrasive pre-form is washed using 15% HCl followed by arinse with de-ionized water. The rinsed article is electroplated withnickel to form a bonding layer directly contacting and overlying theabrasive particles and tacking layer.

EXAMPLE 4

A length of high strength carbon steel wire is obtained as a substrate.The high strength carbon steel wire has an average diameter ofapproximately 120 microns. A tacking layer is formed on the externalsurface of the substrate via electroplating. The electroplating processforms a tacking layer having an average thickness of approximately 2microns. The tacking layer is formed of a high purity tin composition(99.9% pure tin).

After forming the tacking layer, the wire is spooled into a bathcontaining a liquid flux material commercially available as Stay Clean®Liquid Soldering Flux from Harris Products Group and nickel-coateddiamond abrasive particles having an average particle size of between 10to 20 microns are mixed with the flux. Thereafter, the substrate,tacking layer, and abrasive particles are heat treated to a temperatureto approximately 250° C. The abrasive pre-form is then cooled andrinsed. The process of bonding the nickel coated diamond to the tackinglayer is conducted at an average spooling rate of 15 m/min.

Thereafter, the abrasive pre-form is washed using 15% HCl followed by arinse with de-ionized water. The rinsed article is electroplated withnickel to form a bonding layer directly contacting and overlying theabrasive particles and tacking layer.

By controlling the concentration of nickel-coated diamond abrasiveparticles within the flux, diamond concentrations on the wire areobtained with a range that includes 60 particles per millimeter of wireand 600 particles per millimeter of wire. This corresponds to about 0.6to 6.0 carats per kilometer of 120 micron steel wire. FIG. 5 depicts awire 500 with a concentration of approximately 60 particles 502 permillimeter of wire and FIG. 6 depicts a wire 600 with a concentration ofapproximately 600 particles 602 per millimeter of wire.

Cutting Test:

One 100 mm square brick of silicon is provided as a workpiece And 365meters of wire produced in accordance with Example 4 is provided. Thewire includes an abrasive particle concentration of about 1.0 carats permeter of wire. The wire operates at a speed of 9 meters per second and awire tension of 14 Newtons. The cutting time is 120 minutes. The wiresuccessfully cut through the workpieces and produced 12 wafers with asingle cut.

Eds Analysis:

An EDS analysis of the wire of Example 4 shows no indication ofprecipitates formed. Referring to FIG. 7, the results of the EDSanalysis shows the steel wire 702 and a layer of tin 704 is disposed onthe steel wire 702. Further, a layer of nickel is disposed on the tin704. In FIG. 8, the results of the EDS analysis also indicates a nickellayer 802 is formed around the diamond 804 such that the diamond 804 isnearly completely coated with the nickel layer 802. Further, the nickellayer 802 forms an interface with the tin layer 806 that is deposited onthe steel core 808.

EXAMPLE 5

A length of high strength carbon steel wire is obtained as a substrate.The high strength carbon steel wire has an average diameter ofapproximately 120 microns. A tacking layer is formed on the externalsurface of the substrate via dip coating. The dip coating process formsa tacking layer having an average thickness of approximately 2 microns.The tacking layer is formed of an essentially of tin composition.

After forming the tacking layer, the wire is spooled into a bathcontaining a liquid flux material commercially available as Stay Clean®Liquid Soldering Flux from Harris Products Group and the treated wire isthen sprayed with nickel-coated diamond abrasive particles having anaverage particle size of between 10 to 20 microns. Unfortunately, forreasons not quite understood, the abrasive particles do not adhere tothe tacking layer formed via dip coating and the remaining process stepsare not performed.

Due to a lack of abrasive particles on the substrate, an abrasivearticle formed in a manner similar to Example 5 would lack a usableamount of abrasive particles and the abrasive article would be untenableas an abrasive cutting tool.

EXAMPLE 6

A length of high strength carbon steel wire is obtained as a substrate.The high strength carbon steel wire has an average diameter ofapproximately 120 microns. A tacking layer is formed on the externalsurface of the substrate via electroplating. The electroplating processforms a tacking layer having an average thickness of approximately 1.5micron. The tacking layer is formed of a matte tin compositioncomprising not greater than about 0.1% of organics, and essentially freeof organic brighteners and organic grain refiners. The matte tinmaterial comprises 99.9% pure tin. The average grain size of the platedtin ranges from about 0.5 to 5 microns.

After forming the tacking layer, the wire is spooled into a bathcontaining a liquid flux material commercially available as Stay Clean®Liquid Soldering Flux from Harris Products Group and nickel-coateddiamond abrasive particles having an average particle size of between 10to20 microns are mixed with the flux. The viscosity of the slurry isabout 1 mPa s at temperature of 25° C. Thereafter, the substrate,tacking layer, and abrasive particles are heat treated to a temperatureto approximately 250° C. The abrasive pre-form is then cooled andrinsed.

The process of bonding the nickel coated diamond to the tacking layer isconducted at an average spooling rate of 15 m/min. Thereafter, theabrasive pre-form is washed using 15% HCl followed by a rinse withde-ionized water. The rinsed article is electroplated with nickel toform a bonding layer directly contacting and overlying the abrasiveparticles and tacking layer.

EXAMPLE 7

A length of high strength carbon steel wire is obtained as a substrate.The high strength carbon steel wire has an average diameter ofapproximately 120 microns. A tacking layer is formed on the externalsurface of the substrate via electroplating. The electroplating processforms a tacking layer having an average thickness of approximately 1.5micron. The tacking layer is formed of a high purity tin or tinsoldering composition (e.g., 60/40 tin/lead composition).

After forming the tacking layer, the wire is spooled into a bathcontaining a liquid flux material commercially available as Stay Clean®Liquid Soldering Flux from Harris Products Group and nickel-coateddiamond abrasive particles having an average particle size of between 10to 20 microns are mixed with the flux. Thereafter, the substrate,tacking layer, and abrasive particles are heat treated to a temperatureto approximately 250° C. The abrasive pre-form is then cooled andrinsed. Notably, the process facilitates the formation of abrasiveagglomerates 1301, such as those illustrated in FIG. 13. The content ofnickel-coated diamond abrasive particles in the slurry is greater than10% of the total weight of the slurry, thus facilitating the formationof agglomerated particles. The degree of the abrasive agglomerationincreases with the amount of diamond abrasive particles in the slurry.

The process of bonding the nickel coated diamond to the tacking layer isconducted at an average spooling rate of 15 m/min. Thereafter, theabrasive pre-form is washed using 15% HCl followed by a rinse withde-ionized water. The rinsed article is electroplated with nickel toform a bonding layer directly contacting and overlying the abrasiveparticles and tacking layer.

Wafer Break Strength Test:

Wafer break strength test is conducted on a Sintech tester with ring onring configuration. The diameter of the support ring is about 57.2 mmand the diameter of the load ring is about 28.6 mm The loading speed isabout 0.5 mm/min. Wafer break strength is calculated by the break loadand the average of wafer thickness.

A 125 mm pseudo square moncrystalline material was sliced to form wafersby two abrasive samples, a first sample (51) representative of anabrasive article formed according to Example 7 and a conventional sampleformed by direct plating of Nickel coated diamond without a tackinglayer. A second 125 mm square multicrystalline silicon material was alsosliced by sample S1 and the conventional sample.

The silicon was sliced under the conditions indicated below in Table 1.

Cutting Machine DWT RTD Wire Saw Machine condition Wire speed (m/s) 9.1Wire tension (N) 14 Workpiece 125 mm silicon # of wafers per cut 12Length of wire used 360 (M) Coolant water soluble

After slicing, the quality of the cut, including measure of damage tothe wafer by the slicing operation was evaluated by measuring theaverage wafer break strength. As illustrated in FIG. 14, the wafersformed by sample S1 for the monocrystalline material and themulticrystalline material had a relative average break strength of atleast about 20% improved over the wafers formed by the conventionalsample. The data demonstrates a remarkable improvement in the quality ofwafers formed using sample S1 over the conventional sample.

The surface roughness, as measured by Ra value, of the wafers sliced bysample S1 is essentially same to the conventional sample. The TTV (totalthickness variation) of the wafers sliced by sample S1 shows 10 to 20%improvement (10-20% lower) than the conventional sample. Additionally,the diamond loss of the sample S1 is 20 to 50% lower than theconventional sample and hence longer wire life is expected for sampleS1.

EXAMPLE 8

A wire sample is formed according to Example 7. The wire is used toconduct a cutting test on a workpiece of monocrystalline silicon wafersinto 156 mm diameter wafers using a Meyer Burger DS265 DW Wire Sawmachine. The slicing test was conducted with water soluble coolant, 15meter per second wire speed, 25 Newton tension, VWSR parameter equal to3 and about 96 seconds per cycle of wire reciprocating. The slicing testwas completed in about 4 hours. The wafers produced had an averagetotall thickness variation (TTV) of less than 20 microns and a surfaceroughness (Ra) of approximately 0.3 um Ra.

EXAMPLE 9

A length of high strength carbon steel wire is obtained as a substrate.The high strength carbon steel wire has an average diameter ofapproximately 180 or 250 microns. A tacking layer is formed on theexternal surface of the substrate via electroplating having an averagethickness of approximately 4 microns. The tacking layer is formed of ahigh purity tin composition (99.9% tin).

After forming the tacking layer, the wire is spooled into a bathcontaining a mixture of flux paste material commercially available asTaramet Sterling Lead-Free Water Soluble Flux from WorthingtonCylinders, DI water, and nickel-coated diamond abrasive particles havingan average particle size of between 30 to 40 microns. The mixture is 64weight % (71 volume %) DI water, 21 weight % (25 volume %) flux pasteand 14 weight % (4 volume %) 30-40 um diamond. After sufficientlycoating, the substrate, tacking layer, and abrasive particles containingmixture are heat treated to a temperature to approximately 250° C. Theabrasive pre-form is then cooled and rinsed. The resulting concentrationof diamond on the wire is approximately 16 ct/km The process of bondingthe nickel coated diamond to the tacking layer is conducted viaelectroplating at an average spooling rate of 6.5 m/min and results in a7-8 um thick bonding layer of nickel.

A 4 inch round crystalline sapphire workpiece was provided forconducting a cutting operation. The workpiece was sliced to form 4wafers using a first sample (S1) representative of an abrasive articleof Example 9. Additionally, 4 wafers were cut from the workpiece using aconventional wire saw (Sample C1) available from Asahi, and commerciallyavailable as Eco MEP Electroplated Wire. The workpiece was sliced underthe conditions indicated below in Table 2 below.

TABLE 2 Cutting Machine Takatori WSD-K2 Machine condition Wire speed(m/s) 10 Table speed (mm/min)  0.12 Wire tension (N) 30 Workpiece 4 inchround sapphire New wire feed (m/min)  0.6 Accel/Decel 3 seconds/3seconds Time at const wire speed (s) 50 Rocking 5 degree at 500 deg/min# of wafers per cut  4 Coolant Oil based

After completing the cutting operation, the quality of the wafers formedfrom the workpiece was evaluated. The evaluation included a generalmeasure of damage to the wafer by the slicing operation includinganalysis of total thickness variation (TTV), bow, and surface roughness(Ra) of each of the wafers. As illustrated in Table 3 below, the wafersformed by sample S1 for the sapphire had a bow that was approximately50% lower (i.e., 50% improvement) with comparable TTV and Ra. The datademonstrates a remarkable improvement in the quality of wafers formedusing sample S1 over the conventional sample (C1).

TABLE 3 Characteristic Specification Sample C1 Sample S1 TTV UCL <30microns 19 ± 12 20 + 12 Bow <30 microns 26 + 7  11 + 7  Ra  <3 microns~0.5 ~0.5

EXAMPLES 10 and 11

A length of high strength carbon steel wire is obtained as a substrate.The high strength carbon steel wire has an average diameter ofapproximately 180 microns. A tacking layer is formed on the externalsurface of the substrate via electroplating having an average thicknessof approximately 4 microns. The tacking layer is formed of a high puritytin composition (99.9% tin).

For Example 10, after forming the tacking layer, a portion of the wireis spooled into a bath containing a mixture of flux paste materialcommercially available as Taramet Sterling Lead-Free Water Soluble Fluxfrom Worthington Cylinders, DI water, nickel-coated diamond abrasiveparticles having an average particle size of between 8 to 16 microns,and nickel-coated diamond abrasive particles having an average particlesize of between 30 to 40 microns. The mixture has a ratio of the 8/16micron particles to the 30/40 micron particles of about 1:1 based on thenumber of abrasive particles, which provides a bimodal abrasive particlesize distribution. The mixture is 61 weight % (71 volume %) hot tapwater, 20 weight % (24 volume %) flux paste and 18 weight % (5 volume %)diamond. After sufficiently coating, the substrate, tacking layer, andabrasive particles containing mixture are heat treated to a temperatureto approximately 250° C. The abrasive pre-form is then cooled andrinsed.

For Example 11, after forming the tacking layer, a portion of the wireis spooled into a bath containing a mixture of flux paste materialcommercially available as Taramet Sterling Lead-Free Water Soluble Fluxfrom Worthington Cylinders, DI water and nickel-coated diamond abrasiveparticles having an average particle size of between 30 to 40 microns.The mixture is 61 weight % (71 volume %) hot tap water, 20 weight % (24volume %) flux paste and 18 weight % (5 volume %) diamond. Aftersufficiently coating, the substrate, tacking layer, and abrasiveparticles containing mixture are heat treated to a temperature toapproximately 250° C. The abrasive pre-form is then cooled and rinsed.

A 4 inch round crystalline sapphire workpiece was provided forconducting a cutting operation. The workpiece was sliced to form 4wafers using a first sample (S1) representative of an abrasive articleof Example 10. Additionally, 4 wafers were cut from the workpiece usinga second sample (S2) representative of an abrasive article of Example11. The workpiece was sliced under the conditions indicated below inTable 4 below.

TABLE 4 Cutting Machine Takatori WSD-K2 Machine condition Ingot Material& Size 4″ Sapphire, C-Plane Wire speed (m/min) 400 Wire tension (N)  30Time of Cut (hrs:mins) 9 Hours and 46 minutes Rocking Angle (Degrees) 5degrees Rocking Speed (degrees/min) 500 # of wafers per cut  4 CoolantOil based

After completing the cutting operation, the quality of the wafers formedfrom the workpiece was evaluated. The evaluation included a generalmeasure of damage to the wafer by the slicing operation includinganalysis of total thickness variation (TTV), bow, and surface roughness(Ra) of each of the wafers. As illustrated in Table 5 below, the wafersformed by samples S1 and S2 for the sapphire had comparable bow, TTV andRa. The evaluation also included a general measure of the cutting forceexerted by the samples. Measurements for cutting force were collectedusing a Kistler 9601A load cell, Kistler 5010 dual mode charge amplifierat a sampleing frequency of 10 Hz. The cutting force of Sample 1 wasabout 20% lower than that of Sample 2.

TABLE 5 Characteristic Sample S1 Sample S2 TTV 20 20 Bow 15 15 Ra 0.40.4 Cutting force at 1.6 2.0 80% of the cut (N/m)

EXAMPLES 12-14

For Examples 12, 13 and 14, a length of high strength carbon steel wireis obtained as a substrate. The high strength carbon steel wire has anaverage diameter of approximately 120 microns. A tacking layer is formedon the external surface of the substrate via electroplating having anaverage thickness of approximately 1.5 microns. The tacking layer isformed of a high purity tin composition (99.9% tin). After forming thetacking layer, the wire is spooled into a bath containing a mixture offlux material, DI water, and nickel-coated diamond abrasive particleshaving an average particle size of about 14 microns. After sufficientlycoating, the substrate, tacking layer, and abrasive particles containingmixture are heat treated to a temperature to approximately 250° C. Theprocess of bonding the nickel coated diamond to the tacking layer isconducted via electroplating at an average spooling rate of 30 m/min andresults in a about 4 um thick bonding layer of nickel. The abrasivepre-form is then cooled and rinsed.

The concentration of diamond on each newly formed wire is measured bydissolving 100 M of each sample of diamond wire in acid solutionseparately, filtering out the diamond particles from each wire andmeasuring the weight of the diamond particles to calculate theconcentration (ct/km) on each wire. Each of Examples 12, 13 and 14 wereformed to have different concentrations of diamond as indicated in Table6 below.

TABLE 6 EXAMPLE 12 EXAMPLE 13 EXAMPLE 14 Diamond 1.4 2.3 3.8concentration (ct/km) Diamond ~40 ~70 ~120 concentration (#/mm)

Three 5 inch×5 inch Mono silicon pseudo workpieces were provided forconducting a cutting operation. A first workpiece was sliced to form 70wafers using a sample (S1) representative of an abrasive article ofExample 12. A second workpiece was sliced to form 70 wafers each using asample (S2) representative of an abrasive article of Example 11.Finally, a third workpiece was sliced to form 70 wafers each using asample (S3) representative of an abrasive article of Example 12. Theworkpieces were sliced under the conditions indicated below in Table 7below.

TABLE 7 Cutting Machine DWT RTD multi-wire condition saw Wire speed(m/s) 10 Cut time (hour) 3 Wire tension (N) 18 Wire testing (m) 300 WireGuide Pitch 500 (μm) # of wafers cut 70 # of cut per test 2

After completing the cutting operation, the quality of the wafers formedfrom the workpieces was evaluated. The evaluation included a generalmeasure of damage to the wafer by the slicing operation includinganalysis of total thickness variation (TTV) and surface roughness (Ra)of each of the wafers. Additionally, the amount of diamond loss thatoccurred on each of the representative samples (S1, S2 & S3) wasmeasured. Also, the diamond concentration of the used wire samples wascalculated using the method noted above for calculating the diamondconcentration on the new wire samples (i.e., dissolving 100 M of eachsample of diamond wire in acid solution separately, filtering out thediamond particles from each wire and measuring the weight of the diamondparticles to calculate the concentration (ct/km) on each wire). Thediamond concentration of the used wire was then used to calculate thepercent diamond loss for the wire. As illustrated in Table 8 below, thewafers formed by samples S1, S2 and S3 had comparable TTV and Ra.However, samples S2 and S3 had nearly half of the diamond loss of sampleS1, thus indicating improved performance and life of the abrasive wiresamples of S2 and S3 as compared to S1.

TABLE 8 EXAMPLE 12 EXAMPLE 13 EXAMPLE 14 Ra (um) 0.5 0.4 0.4 TTV (um) 1914 16 Diamond 0.4 1.4 2.3 Concentration on Used Wire (ct/km) Diamondloss (%) ~70% ~40% ~40% Wire Wear High Medium Low (qualitative) WireLife Low Higher Higher (qualitative)

EXAMPLE 15

For Example 15, conventional samples of an abrasive article were made byco-depositing 10/20 Ni coated diamond particles with Ni electrolyticplating on 120 micron steel core wire at three different productionrates. FIG. 18A shows a magnified image of a sample of the conventionalwire produced at a production speed of 3 m/min. FIG. 18B shows amagnified image of a sample of the conventional wire produced at aproduction speed of 5 m/min. FIG. 18C shows a magnified image of asample of the conventional wire produced at a production speed of 10m/min. As shown in FIGS. 18A-C, diamond concentration on theconventional wire samples decreased with increased production speed(i.e., conventional wire produced at a production speed of 10 m/min hada lower diamond concentration than conventional wire produced at aproduction speed of 3 m/min).

However, abrasive articles of the embodiments described herein can bemade with a high concentration of abrasive particles per mm of substrate(i.e., at least about 10 particles per mm of substrate) at productionspeeds of 10 m/min or higher.

The present application represents a departure from the state of theart. Notably, the embodiments herein demonstrate improved and unexpectedperformance over conventional wire saws. While not wishing to be boundto a particular theory, it is suggested that combination of certainfeatures including designs, processes, materials, and the like mayfacilitate such improvements. The combination of features can include,but is not limited to, aspects of the substrate and processing, aspectsof the barrier layer and processing techniques, aspects of the tackinglayer and processing techniques, aspects of the abrasive particles,including first and second types of abrasive particles, use ofagglomerated particles and unagglomerated particles, aspects of theparticle coating layers and processing techniques, aspects of thebonding layer and processing techniques, and aspects of the coatinglayer and processing techniques.

The above-disclosed subject matter is to be considered illustrative, andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments, which fall withinthe true scope of the present invention. Thus, to the maximum extentallowed by law, the scope of the present invention is to be determinedby the broadest permissible interpretation of the following claims andtheir equivalents, and shall not be restricted or limited by theforegoing detailed description.

The Abstract of the Disclosure is provided to comply with Patent Law andis submitted with the understanding that it will not be used tointerpret or limit the scope or meaning of the claims. In addition, inthe foregoing Detailed Description of the Drawings, various features maybe grouped together or described in a single embodiment for the purposeof streamlining the disclosure. This disclosure is not to be interpretedas reflecting an intention that the claimed embodiments require morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive subject matter may be directed toless than all features of any of the disclosed embodiments. Thus, thefollowing claims are incorporated into the Detailed Description of theDrawings, with each claim standing on its own as defining separatelyclaimed subject matte

What is claimed is:
 1. An abrasive article comprising: a substratehaving an elongated body; a tacking layer; and a first type of abrasiveparticle overlying the tacking layer and defining a first abrasiveparticle concentration of at least about 10 particles per mm ofsubstrate, wherein at least a portion of the tracking layer is in directcontact with an external surface of the substrate, and wherein thetacking layer comprises an average thickness of at least 11% and notgreater than 80% of an average particle size of the first type ofabrasive particles.
 2. The abrasive article of claim 1, wherein thesubstrate has an elongated body.
 3. The abrasive article of claim 1,wherein the substrate comprises an average length of at least about 50m.
 4. The abrasive article of claim 1, wherein the substrate comprisesan average width of not greater than about 1 mm.
 5. The abrasive articleof claim 1, wherein the substrate comprises a break strength of at leastabout 3 GPa.
 6. The abrasive article of claim 1, wherein the substratecomprises a plurality of filaments braided together.
 7. The abrasivearticle of claim 1, further comprising a barrier layer in direct contactwith a peripheral surface of the substrate.
 8. The abrasive article ofclaim 1, wherein the tacking layer has an average thickness of notgreater than about 10 microns.
 9. The abrasive article of claim 1,wherein the tacking layer comprises an average thickness of not greaterthan about 30% of a total average particle size of the first type ofabrasive particles.
 10. The abrasive article of claim 1, wherein thefirst type of abrasive particle comprises a material selected from thegroup of materials consisting of oxides, carbides, nitrides, borides,oxynitrides, oxyborides, diamond, and a combination thereof.
 11. Theabrasive article of claim 1, wherein the first type of abrasive particlecomprises an average particle size of not greater than about 500microns.
 12. The abrasive article of claim 1, wherein abrasive particleis defined by a wide grit size distribution, wherein at least 80% ofabrasive particles have an average particle size contained within arange of at least about 30 microns over a range of average particlesizes between about 1 micron to about 100 microns.
 13. The abrasivearticle of claim 1, wherein the abrasive particle comprises anagglomerated particle.
 14. The abrasive article of claim 1, wherein theabrasive particle defines a layer of abrasive particles and wherein thelayer of abrasive particles defines a pattern.
 15. The abrasive articleof claim 1, wherein a majority of the abrasive particle is spaced apartfrom the substrate.
 16. The abrasive article of claim 1, wherein theabrasive particle comprises particle coating.
 17. The abrasive articleof claim 1 further comprising a bonding layer directly contacting atleast a portion of the tacking layer.
 18. The abrasive article of claim17, wherein the bonding layer comprises an average thickness of at leastabout 10% of an average particle size of the abrasive particle.
 19. Theabrasive article of claim 1, further comprising a coating layeroverlying the substrate.
 20. The abrasive article of claim 19, whereinthe coating layer overlies at least about 25% of an exterior surfacearea of the abrasive particle.